Buggy python submission (verdict: Time Limit Exceeded):
m_d = list()    # 魔法移動距離
for i in range(-2, 3):
    for j in range(-2, 3):
        if (i,j) not in [(0,0),(-1,0),(0,-1),(1,0),(0,1)]:
            m_d += [(i,j)]

h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+4, w+4), INF)
dist = [[INF for j in range(w+4)] for i in range(h+4)]

# マップ境界を壁で囲む
S = ['##{}##'.format(s_row) for s_row in s]
S = ['##{}##'.format('#' * (w+4))]*2 + S
S = S + ['##{}##'.format('#' * (w+4))]*2

# BFS探索用キュー
from collections import deque
q_a = deque() # 徒歩
q_b = deque() # ワープ

# 開始位置、終了位置を調整
si, sj = si+1, sj+1
ti, tj = ti+1, tj+1
dist[si][sj] = 0
q_a.append([si,sj])

while (len(q_a)>0):
    i, j = ij = q_a.popleft()
    d = dist[i][j]
    for di, dj in [(-1,0),(0,-1),(1,0),(0,1)]:
        ni, nj = di+i, dj+j
        if (S[ni][nj]=='#'):
            q_b.append(ij)
            continue # 壁
        if (dist[ni][nj]<=d):
            continue # 探索済みコスト以上
        dist[ni][nj] = d
        q_a.append([ni,nj])

    if len(q_a) == 0:
        while (len(q_b)>0):
            i, j = q_b.popleft()
            d = dist[i][j]
            for di, dj in m_d:
                ni, nj = di+i, dj+j
                if (S[ni][nj]=='#'):
                    continue # 壁
                if (dist[ni][nj]<=d):
                    continue # 探索済みコスト以上
                dist[ni][nj] = d+1
                q_a.append([ni,nj])

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
m_d = list()    # 魔法移動距離
for i in range(-2, 3):
    for j in range(-2, 3):
        if (i,j) not in [(0,0),(-1,0),(0,-1),(1,0),(0,1)]:
            m_d += [(i,j)]

h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+4, w+4), INF)
dist = [[INF for j in range(w+4)] for i in range(h+4)]

# マップ境界を壁で囲む
S = ['##{}##'.format(s_row) for s_row in s]
S = ['##{}##'.format('#' * (w+4))]*2 + S
S = S + ['##{}##'.format('#' * (w+4))]*2

# BFS探索用キュー
from collections import deque
q_a = deque() # 徒歩
q_b = deque() # ワープ

# 開始位置、終了位置を調整
si, sj = si+1, sj+1
ti, tj = ti+1, tj+1
dist[si][sj] = 0
q_a.append([si,sj])

while (len(q_a)>0):
    i, j = ij = q_a.popleft()
    q_b.append(ij)
    d = dist[i][j]
    for di, dj in [(-1,0),(0,-1),(1,0),(0,1)]:
        ni, nj = di+i, dj+j
        if (S[ni][nj]=='#'):
            continue # 壁
        if (dist[ni][nj]<=d):
            continue # 探索済みコスト以上
        dist[ni][nj] = d
        q_a.append([ni,nj])

    if len(q_a) == 0:
        while (len(q_b)>0):
            i, j = q_b.popleft()
            d = dist[i][j]
            for di, dj in m_d:
                ni, nj = di+i, dj+j
                if (S[ni][nj]=='#'):
                    continue # 壁
                if (dist[ni][nj]<=d):
                    continue # 探索済みコスト以上
                dist[ni][nj] = d+1
                q_a.append([ni,nj])

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
m_d = list()    # 魔法移動距離
for i in range(-2, 3):
    for j in range(-2, 3):
        if (i,j) not in [(0,0),(-1,0),(0,-1),(1,0),(0,1)]:
            m_d += [(i,j)]

h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+4, w+4), INF)
dist = [[INF for j in range(w+4)] for i in range(h+4)]

# マップ境界を壁で囲む
S = ['##{}##'.format(s_row) for s_row in s]
S = ['##{}##'.format('#' * (w+4))]*2 + S
S = S + ['##{}##'.format('#' * (w+4))]*2

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置、終了位置を調整
si, sj = si+1, sj+1
ti, tj = ti+1, tj+1
dist[si][sj] = 0
q.append([si,sj])

while (len(q)>0):
    i, j = q.popleft()
    d = dist[i][j]
    for di, dj in [(-1,0),(0,-1),(1,0),(0,1)]:
        ni, nj = di+i, dj+j
        if (S[ni][nj]=='#'):
            continue # 壁
        if (dist[ni][nj]<=d):
            continue # 探索済みコスト以上
        dist[ni][nj] = d
        q.appendleft([ni,nj])

    for di, dj in m_d:
        ni, nj = di+i, dj+j
        if (S[ni][nj]=='#'):
            continue # 壁
        if (dist[ni][nj]<=d):
            continue # 探索済みコスト以上
        dist[ni][nj] = d+1
        q.append([ni,nj])

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
m_d = list()    # 魔法移動距離
for i in range(-2, 3):
    for j in range(-2, 3):
        if (i,j) not in [(0,0),(-1,0),(0,-1),(1,0),(0,1)]:
            m_d += [(i,j)]

h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+4, w+4), INF)
dist = [[INF for j in range(w+4)] for i in range(h+4)]

# マップ境界を壁で囲む
S = ['##{}##'.format(s_row) for s_row in s]
S = ['##{}##'.format('#' * (w+4))]*2 + S
S = S + ['##{}##'.format('#' * (w+4))]*2

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置、終了位置を調整
si, sj = si+1, sj+1
ti, tj = ti+1, tj+1
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q.popleft()
    d = dist[i][j]
    for di, dj in [(-1,0),(0,-1),(1,0),(0,1)]:
        ni, nj = di+i, dj+j
        if (S[ni][nj]=='#'):
            continue # 壁
        if (dist[ni][nj]<=d):
            continue # 探索済みコスト以上
        dist[ni][nj] = d
        q.appendleft((ni,nj))

    for di, dj in m_d:
        ni, nj = di+i, dj+j
        if (S[ni][nj]=='#'):
            continue # 壁
        if (dist[ni][nj]<=d):
            continue # 探索済みコスト以上
        dist[ni][nj] = d+1
        q.append((ni,nj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
m_d = list()    # 魔法移動距離
for i in range(-2, 3):
    for j in range(-2, 3):
        if (i,j) not in [(0,0),(-1,0),(0,-1),(1,0),(0,1)]:
            m_d += [(i,j)]

h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+4, w+4), INF)
dist = [[INF for j in range(w+4)] for i in range(h+4)]

# マップ境界を壁で囲む
S = ['##{}##'.format(s_row) for s_row in s]
S = ['##{}##'.format('#' * (w+4))]*2 + S
S = S + ['##{}##'.format('#' * (w+4))]*2

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置、終了位置を調整
si, sj = si+1, sj+1
ti, tj = ti+1, tj+1
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q.popleft()
    d = dist[i][j]
    for di, dj in [(-1,0),(0,-1),(1,0),(0,1)]:
        ni, nj = di+i, dj+j
        if (S[ni][nj]=='#'):
            continue # 壁
        if (dist[ni][nj]<=d):
            continue # 探索済みコスト以上
        dist[ni][nj] = d
        q.appendleft((ni,nj))

    for di, dj in m_d:
        ni, nj = di+i, dj+j
        if (S[ni][nj]=='#'):
            continue # 壁
        if (dist[ni][nj]<=d):
            continue # 探索済みコスト以上
        dist[ni][nj] = d+1
        q.append((ni,nj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
d_c = list()
for i in range(-2, 3):
    for j in range(-2, 3):
        if (i,j) == (0,0):
            continue
        elif (i,j) in [(-1,0),(0,-1),(1,0),(0,1)]:
            d_c += [(i,j,0)]   # 歩くコスト
        else:
            d_c += [(i,j,1)]   # 魔法コスト

h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+4, w+4), INF)
dist = [[INF for j in range(w+4)] for i in range(h+4)]

# マップ境界を壁で囲む
S = ['##{}##'.format(s_row) for s_row in s]
S = ['##{}##'.format('#' * (w+4))]*2 + S
S = S + ['##{}##'.format('#' * (w+4))]*2

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置、終了位置を調整
si, sj = si+1, sj+1
ti, tj = ti+1, tj+1
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    for di, dj, c in d_c:
        ni, nj = di+i, dj+j
        if (S[ni][nj]=='#'):
            continue # 壁
        if (dist[ni][nj]<=d):
            continue # 探索済みコスト以上
        dist[ni][nj] = d+c
        if c == 0:
            q.appendleft((ni,nj))
        else:
            q.append((ni,nj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
# 移動Aで探索する方向
d_a = [(-1,0),(0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = list()
for i in range(-2, 3):
    for j in range(-2, 3):
        if (i,j) not in (d_a+[(0,0)]):
            d_b += [(i,j)]

h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+4, w+4), INF)
dist = [[INF for j in range(w+4)] for i in range(h+4)]

# マップ境界を壁で囲む
S = ['##{}##'.format(s_row) for s_row in s]
S = ['##{}##'.format('#' * (w+4))]*2 + S
S = S + ['##{}##'.format('#' * (w+4))]*2

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置、終了位置を調整
si, sj = si+1, sj+1
ti, tj = ti+1, tj+1
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    close_wall = False
    # 移動Aによるコスト
    for di, dj in d_a:
        di, dj = di+i, dj+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (S[di][dj]=='#'):
            close_wall = True
            continue # 壁
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 壁際ならば移動Bによるコストを探索
    if close_wall:
        for di, dj in d_b:
            di, dj = di+i, dj+j
            if (S[di][dj]=='#'):
                continue # 壁
            if (dist[di][dj]<=d):
                continue # 探索済みコスト以上
            dist[di][dj] = d+1
            q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
# 移動Aで探索する方向
d_a = [(-1,0),(0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = list()
for i in range(-2, 3):
    for j in range(-2, 3):
        if (i,j) not in (d_a+[(0,0)]):
            d_b += [(i,j)]

h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+4, w+4), INF)
dist = [[INF for j in range(w+4)] for i in range(h+4)]

# マップ境界を壁で囲む
S = ['##{}##'.format(s_row) for s_row in s]
S = ['##{}##'.format('#' * (w+4))]*2 + S
S = S + ['##{}##'.format('#' * (w+4))]*2

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置、終了位置を調整
si, sj = si+1, sj+1
ti, tj = ti+1, tj+1
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for di, dj in d_a:
        di, dj = di+i, dj+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (S[di][dj]=='#'):
            continue # 壁
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for di, dj in d_b:
        di, dj = di+i, dj+j
        if (S[di][dj]=='#'):
            continue # 壁
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
# 移動Aで探索する方向
d_a = [(-1,0),(0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = list()
for i in range(-2, 3):
    for j in range(-2, 3):
        if (i,j) not in (d_a+[(0,0)]):
            d_b += [(i,j)]

h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+4, w+4), INF)
dist = [[INF for j in range(w+4)] for i in range(h+4)]

# マップ境界と壁を距離0にして探索させない
for i in range(len(dist)):
    dist[i][0] = 0
    dist[i][1] = 0
    dist[i][-1] = 0
    dist[i][-2] = 0
for j in range(len(dist[0])):
    dist[0][j] = 0
    dist[1][j] = 0
    dist[-1][j] = 0
    dist[-2][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+2][j+2] = 0

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置、終了位置を調整
si, sj = si+1, sj+1
ti, tj = ti+1, tj+1
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for di, dj in d_a:
        di, dj = di+i, dj+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for di, dj in d_b:
        di, dj = di+i, dj+j
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
# 移動Aで探索する方向
d_a = [(-1,0),(0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = list()
for i in range(-2, 3):
    for j in range(-2, 3):
        if not((i,j) in d_a) and ((i,j) != (0,0)):
            d_b += [(i,j)]

h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+4, w+4), INF)
dist = [[INF for j in range(w+4)] for i in range(h+4)]

# マップ境界と壁を距離0にして探索させない
for i in range(len(dist)):
    dist[i][0] = 0
    dist[i][1] = 0
    dist[i][-1] = 0
    dist[i][-2] = 0
for j in range(len(dist[0])):
    dist[0][j] = 0
    dist[1][j] = 0
    dist[-1][j] = 0
    dist[-2][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+2][j+2] = 0

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置、終了位置を調整
si, sj = si+1, sj+1
ti, tj = ti+1, tj+1
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        di, dj = d_b[v][0]+i, d_b[v][1]+j
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+4, w+4), INF)
dist = [[INF for j in range(w+4)] for i in range(h+4)]

# マップ境界と壁を距離0にして探索させない
for i in range(len(dist)):
    dist[i][0] = 0
    dist[i][1] = 0
    dist[i][-1] = 0
    dist[i][-2] = 0
for j in range(len(dist[0])):
    dist[0][j] = 0
    dist[1][j] = 0
    dist[-1][j] = 0
    dist[-2][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+2][j+2] = 0

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置、終了位置を調整
si, sj = si+1, sj+1
ti, tj = ti+1, tj+1
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        di, dj = d_b[v][0]+i, d_b[v][1]+j
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Runtime Error):
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+4, w+4), INF)
dist = [[INF for j in range(w+4)] for i in range(h+4)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][1] = 0
    dist[i][-1] = 0
    dist[i][-2] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[1][j] = 0
    dist[-1][j] = 0
    dist[-2][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+2][j+2] = 0

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置、終了位置を調整
si, sj = si+1, sj+1
ti, tj = ti+1, tj+1
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        di, dj = d_b[v][0]+i, d_b[v][1]+j
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
import numpy as np
INF = int(1e9)
dist = np.full((h+2, w+2), INF)
#dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Runtime Error):
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i, 0] = 0
    dist[i, -1] = 0
for j in range(w+2):
    dist[0, j] = 0
    dist[-1, j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
import numpy as np
INF = int(1e9)
dist = np.full((h+2, w+2), INF)

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i, 0] = 0
    dist[i, -1] = 0
for j in range(w+2):
    dist[0, j] = 0
    dist[-1, j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
h, w = list(map(int, input().split()))
si, sj = list(map(lambda x: int(x)-1, input().split()))
ti, tj = list(map(lambda x: int(x)-1, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 探索時に移動する方向
di = [-1, 0, 1, 0]
dj = [0, -1, 0, 1]

# 距離情報を一番遠い値で初期化
import numpy as np
INF = int(1e9)
dist = np.full((h, w), INF)
#dist = [[INF for j in range(w)] for i in range(h)]

from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    (i, j) = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(di)):
        ni, nj = i+di[v], j+dj[v]
        if (ni<0 or ni>=h or nj<0 or nj>=w):
            continue # マップの境界
        if (s[ni][nj] == '#'):
            continue # 壁
        if (dist[ni][nj]<=d):
            continue # 探索済みコスト以上
        dist[ni][nj] = d
        q.appendleft((ni, nj))
    # 移動Bによるコスト
    for ei in range(-2, 3):
        for ej in range(-2, 3):
            ni, nj = i+ei, j+ej
            if (ni<0 or ni>=h or nj<0 or nj>=w):
                continue # マップの境界
            if (s[ni][nj] == '#'):
                continue # 壁
            if (dist[ni][nj]<=d):
                continue # 探索済みコスト以上
            dist[ni][nj] = d+1
            q.append((ni, nj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
h, w = list(map(int, input().split()))
si, sj = list(map(lambda x: int(x)-1, input().split()))
ti, tj = list(map(lambda x: int(x)-1, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 探索時に移動する方向
di = [-1, 0, 1, 0]
dj = [0, -1, 0, 1]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h, w), INF)
dist = [[INF for j in range(w)] for i in range(h)]

from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    (i, j) = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(di)):
        ni, nj = i+di[v], j+dj[v]
        if (ni<0 or ni>=h or nj<0 or nj>=w):
            continue # マップの境界
        if (s[ni][nj] == '#'):
            continue # 壁
        if (dist[ni][nj]<=d):
            continue # 探索済みコスト以上
        dist[ni][nj] = d
        q.append((ni, nj))
    # 移動Bによるコスト
    for ei in range(-2, 3):
        for ej in range(-2, 3):
            ni, nj = i+ei, j+ej
            if (ni<0 or ni>=h or nj<0 or nj>=w):
                continue # マップの境界
            if (s[ni][nj] == '#'):
                continue # 壁
            if (dist[ni][nj]<=d):
                continue # 探索済みコスト以上
            dist[ni][nj] = d+1
            q.append((ni, nj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
h, w = list(map(int, input().split()))
si, sj = list(map(lambda x: int(x)-1, input().split()))
ti, tj = list(map(lambda x: int(x)-1, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 探索時に移動する方向
di = [-1, 0, 1, 0]
dj = [0, -1, 0, 1]

# 距離情報を一番遠い値で初期化
import numpy as np
INF = int(1e9)
dist = np.full((h, w), INF)

from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    (i, j) = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(di)):
        ni, nj = i+di[v], j+dj[v]
        if (ni<0 or ni>=h or nj<0 or nj>=w):
            continue # マップの境界
        if (s[ni][nj] == '#'):
            continue # 壁
        if (dist[ni][nj]<=d):
            continue # 探索済みコスト以上
        dist[ni][nj] = d
        q.append((ni, nj))
    # 移動Bによるコスト
    for ei in range(-2, 3):
        for ej in range(-2, 3):
            ni, nj = i+ei, j+ej
            if (ni<0 or ni>=h or nj<0 or nj>=w):
                continue # マップの境界
            if (s[ni][nj] == '#'):
                continue # 壁
            if (dist[ni][nj]<=d):
                continue # 探索済みコスト以上
            dist[ni][nj] = d+1
            q.append((ni, nj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)

Buggy python submission (verdict: Runtime Error):
h, w = list(map(int, input().split()))
si, sj = list(map(lambda x: int(x)-1, input().split()))
ti, tj = list(map(lambda x: int(x)-1, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 探索時に移動する方向
di = [-1, 0, 1, 0]
dj = [0, -1, 0, 1]

# 距離情報を一番遠い値で初期化
import numpy as np
INF = int(1e9)
dist = np.full((h, w), INF)

from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    (i, j) = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(di)):
        ni, nj = i+di[v], j+dj[v]
        if (ni<0 or ni>=h or nj<0 or nj>=w):
            continue # マップの境界
        if (s[ni][nj] == '#'):
            continue # 壁
        if (dist[ni][nj]<=d):
            continue # 探索済みコスト以上
        dist[ni][nj] = d
        q.append((ni, nj))
    # 移動Bによるコスト
    for ei in range(-2, 3):
        for ej in range(-2, 3):
            ni, nj = i+ei, j+ej
            if (ni<0 or ni>=h or nj<0 or nj>=w):
                continue # マップの境界
            if (s[ni][nj] == '#'):
                continue # 壁
            if (dist[ni][nj]<=d):
                continue # 探索済みコスト以上
            dist[ni][nj] = d+1
            q.append((ni, nj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)


Fixed submission:
h, w = list(map(int, input().split()))
si, sj = list(map(int, input().split()))
ti, tj = list(map(int, input().split()))
s = [None] * h
for i in range(h):
    s[i] = input()

# 移動Aで探索する方向
d_a = [(-1,0), (0,-1),(1,0),(0,1)]
# 移動Bで探索する方向
d_b = [ (i, j) for j in range(-2, 3) for i in range(-2, 3)]

# 距離情報を一番遠い値で初期化
#import numpy as np
INF = int(1e9)
#dist = np.full((h+2, w+2), INF)
dist = [[INF for j in range(w+2)] for i in range(h+2)]

# マップ境界と壁を距離0にして探索させない
for i in range(h+2):
    dist[i][0] = 0
    dist[i][-1] = 0
for j in range(w+2):
    dist[0][j] = 0
    dist[-1][j] = 0
for i in range(h):
    for j in range(w):
        if s[i][j]=='#': dist[i+1][j+1] = 0
#dist = [[INF for j in range(w)] for i in range(h)]

# 01-BFS探索用キュー
from collections import deque
q = deque()

# 開始位置
dist[si][sj] = 0
q.append((si,sj))

while (len(q)>0):
    i, j = q[0]
    d = dist[i][j]
    q.popleft()
    # 移動Aによるコスト
    for v in range(len(d_a)):
        di, dj = d_a[v][0]+i, d_a[v][1]+j
        if (di, dj) == (ti, tj):
            print(d)
            exit(0)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d
        q.appendleft((di, dj))
    # 移動Bによるコスト
    for v in range(len(d_b)):
        # マップ境界で2以上移動したときに、反対の境界に向かうように剰余を取る
        di, dj = (d_b[v][0]+i)%(h+2), (d_b[v][1]+j)%(w+2)
        if (dist[di][dj]<=d):
            continue # 探索済みコスト以上
        dist[di][dj] = d+1
        q.append((di, dj))

ans = dist[ti][tj]
if ans == INF:
    ans = -1
print(ans)