Buggy python submission (verdict: Runtime Error):
import collections
import itertools
N = int(input())
#cnt[URLD][x y y+x y-x][value]=set()
cnt = [[collections.defaultdict(set) for _ in range(4)] for _ in range(4)]
for _ in range(N):
    x, y, u = input().split()
    x = int(x)
    y = int(y)
    p = y + x
    q = y - x
    i = 'URLD'.index(u)
    cnt[i][0][x].add(y)
    cnt[i][1][y].add(x)
    cnt[i][2][p].add(q)
    cnt[i][3][q].add(p)

INF = float('inf')


def calc(up, down):
    ret = INF
    lower = -INF
    upper = INF
    for c in up.keys() & down.keys():
        for v, d in = sorted({(v, 0) for v in up[c]} | {(v, 1) for v in down[c]}):
            if d:
                upper = v
            else:
                lower = v
            ret=min(ret,upper-lower)
    return ret


#U(0)とD(3)がx(0)が一緒:d-u(>=0)の最小値
#R(1)とL(2)がy(1)が一緒:l-r(>=0)の最小値
#U(0)とR(1)がx+y(2)が一緒:(y-x)のr-u(>=0)の最小値
#L(2)とD(3)がx+y(2)が一緒:(y-x)のd-l(>=0)の最小値
#U(0)とL(2)がy-x(3)が一緒:(y+x)のl-u(>=0)の最小値
#R(1)とD(3)がy-x(3)が一緒:(y+x)のd-r(>=0)の最小値
ans = min(
    calc(cnt[0][0], cnt[3][0]), calc(cnt[1][1], cnt[2][1]),
    calc(cnt[0][2], cnt[1][2]), calc(cnt[2][2], cnt[3][2]),
    calc(cnt[0][3], cnt[2][3]), calc(cnt[1][3], cnt[3][3]))
print('SAFE' if ans == INF else ans * 5)


Fixed submission:
import collections
import itertools
N = int(input())
#cnt[URLD][x y y+x y-x][value]=set()
cnt = [[collections.defaultdict(set) for _ in range(4)] for _ in range(4)]
for _ in range(N):
    x, y, u = input().split()
    x = int(x)
    y = int(y)
    p = y + x
    q = y - x
    i = 'URLD'.index(u)
    cnt[i][0][x].add(y)
    cnt[i][1][y].add(x)
    cnt[i][2][p].add(q)
    cnt[i][3][q].add(p)

INF = float('inf')


def calc(up, down):
    ret = [INF]
    for c in up.keys() & down.keys():
        ua = sorted(up[c])
        da = sorted(down[c])
        i = j = 0
        for i in range(len(ua)):
            for j in range(j, len(da)):
                if ua[i] < da[j]:
                    ret += [da[j] - ua[i]]
                    break
            i += 1
    return min(ret)


#U(0)とD(3)がx(0)が一緒:d-u(>=0)の最小値
#R(1)とL(2)がy(1)が一緒:l-r(>=0)の最小値
#U(0)とR(1)がx+y(2)が一緒:(y-x)のr-u(>=0)の最小値
#L(2)とD(3)がx+y(2)が一緒:(y-x)のd-l(>=0)の最小値
#U(0)とL(2)がy-x(3)が一緒:(y+x)のl-u(>=0)の最小値
#R(1)とD(3)がy-x(3)が一緒:(y+x)のd-r(>=0)の最小値
ans = min(
    calc(cnt[0][0], cnt[3][0]), calc(cnt[1][1], cnt[2][1]),
    calc(cnt[0][2], cnt[1][2]), calc(cnt[2][2], cnt[3][2]),
    calc(cnt[0][3], cnt[2][3]), calc(cnt[1][3], cnt[3][3]))
print('SAFE' if ans == INF else ans * 5)

Buggy python submission (verdict: Runtime Error):
import collections
import itertools
N = int(input())
#cnt[URLD][x y y+x y-x][value]=set()
cnt = [[collections.defaultdict(set) for _ in range(4)] for _ in range(4)]
for _ in range(N):
    x, y, u = input().split()
    x = int(x)
    y = int(y)
    p = y + x
    q = y - x
    i = 'URLD'.index(u)
    cnt[i][0][x].add(y)
    cnt[i][1][y].add(x)
    cnt[i][2][p].add(q)
    cnt[i][3][q].add(p)

INF = float('inf')


def calc(up, down):
    ret = [INF]
    for c in up.keys() & down.keys():
        ua = sorted(up[c])
        da = sorted(down[c])
        i = j = 0
        if len(ua) and len(da):
            for i in range(len(ua)):
                for j in range(j, len(da)):
                    if ua[i] < da[j]:
                        ret += [da[i] - ua[i]]
                        break
                i += 1
    return min(ret)


#U(0)とD(3)がx(0)が一緒:d-u(>=0)の最小値
#R(1)とL(2)がy(1)が一緒:l-r(>=0)の最小値
#U(0)とR(1)がx+y(2)が一緒:(y-x)のr-u(>=0)の最小値
#L(2)とD(3)がx+y(2)が一緒:(y-x)のd-l(>=0)の最小値
#U(0)とL(2)がy-x(3)が一緒:(y+x)のl-u(>=0)の最小値
#R(1)とD(3)がy-x(3)が一緒:(y+x)のd-r(>=0)の最小値
ans = min(
    calc(cnt[0][0], cnt[3][0]), calc(cnt[1][1], cnt[2][1]),
    calc(cnt[0][2], cnt[1][2]), calc(cnt[2][2], cnt[3][2]),
    calc(cnt[0][3], cnt[2][3]), calc(cnt[1][3], cnt[3][3]))
print('SAFE' if ans == INF else ans * 5)


Fixed submission:
import collections
import itertools
N = int(input())
#cnt[URLD][x y y+x y-x][value]=set()
cnt = [[collections.defaultdict(set) for _ in range(4)] for _ in range(4)]
for _ in range(N):
    x, y, u = input().split()
    x = int(x)
    y = int(y)
    p = y + x
    q = y - x
    i = 'URLD'.index(u)
    cnt[i][0][x].add(y)
    cnt[i][1][y].add(x)
    cnt[i][2][p].add(q)
    cnt[i][3][q].add(p)

INF = float('inf')


def calc(up, down):
    ret = [INF]
    for c in up.keys() & down.keys():
        ua = sorted(up[c])
        da = sorted(down[c])
        i = j = 0
        for i in range(len(ua)):
            for j in range(j, len(da)):
                if ua[i] < da[j]:
                    ret += [da[j] - ua[i]]
                    break
            i += 1
    return min(ret)


#U(0)とD(3)がx(0)が一緒:d-u(>=0)の最小値
#R(1)とL(2)がy(1)が一緒:l-r(>=0)の最小値
#U(0)とR(1)がx+y(2)が一緒:(y-x)のr-u(>=0)の最小値
#L(2)とD(3)がx+y(2)が一緒:(y-x)のd-l(>=0)の最小値
#U(0)とL(2)がy-x(3)が一緒:(y+x)のl-u(>=0)の最小値
#R(1)とD(3)がy-x(3)が一緒:(y+x)のd-r(>=0)の最小値
ans = min(
    calc(cnt[0][0], cnt[3][0]), calc(cnt[1][1], cnt[2][1]),
    calc(cnt[0][2], cnt[1][2]), calc(cnt[2][2], cnt[3][2]),
    calc(cnt[0][3], cnt[2][3]), calc(cnt[1][3], cnt[3][3]))
print('SAFE' if ans == INF else ans * 5)

Buggy python submission (verdict: Runtime Error):
import collections
import itertools
N = int(input())
#cnt[URLD][x y y+x y-x][value]=set()
cnt = [[collections.defaultdict(set) for _ in range(4)] for _ in range(4)]
for _ in range(N):
    x, y, u = input().split()
    x = int(x)
    y = int(y)
    p = y + x
    q = y - x
    i = 'URLD'.index(u)
    cnt[i][0][x].add(y)
    cnt[i][1][y].add(x)
    cnt[i][2][p].add(q)
    cnt[i][3][q].add(p)

INF = float('inf')


def calc(up, down):
    ret = [INF]
    for c in up.keys() & down.keys():
        ua = sorted(up[c])
        da = sorted(down[c])
        i = j = 0
        for i in range(len(ua)):
            for j in range(j, len(da)):
                if ua[i] < da[j]:
                    ret += [da[i] - ua[i]]
                    break
            i += 1
    return min(ret)


#U(0)とD(3)がx(0)が一緒:d-u(>=0)の最小値
#R(1)とL(2)がy(1)が一緒:l-r(>=0)の最小値
#U(0)とR(1)がx+y(2)が一緒:(y-x)のr-u(>=0)の最小値
#L(2)とD(3)がx+y(2)が一緒:(y-x)のd-l(>=0)の最小値
#U(0)とL(2)がy-x(3)が一緒:(y+x)のl-u(>=0)の最小値
#R(1)とD(3)がy-x(3)が一緒:(y+x)のd-r(>=0)の最小値
ans = min(
    calc(cnt[0][0], cnt[3][0]), calc(cnt[1][1], cnt[2][1]),
    calc(cnt[0][2], cnt[1][2]), calc(cnt[2][2], cnt[3][2]),
    calc(cnt[0][3], cnt[2][3]), calc(cnt[1][3], cnt[3][3]))
print('SAFE' if ans == INF else ans * 5)


Fixed submission:
import collections
import itertools
N = int(input())
#cnt[URLD][x y y+x y-x][value]=set()
cnt = [[collections.defaultdict(set) for _ in range(4)] for _ in range(4)]
for _ in range(N):
    x, y, u = input().split()
    x = int(x)
    y = int(y)
    p = y + x
    q = y - x
    i = 'URLD'.index(u)
    cnt[i][0][x].add(y)
    cnt[i][1][y].add(x)
    cnt[i][2][p].add(q)
    cnt[i][3][q].add(p)

INF = float('inf')


def calc(up, down):
    ret = [INF]
    for c in up.keys() & down.keys():
        ua = sorted(up[c])
        da = sorted(down[c])
        i = j = 0
        for i in range(len(ua)):
            for j in range(j, len(da)):
                if ua[i] < da[j]:
                    ret += [da[j] - ua[i]]
                    break
            i += 1
    return min(ret)


#U(0)とD(3)がx(0)が一緒:d-u(>=0)の最小値
#R(1)とL(2)がy(1)が一緒:l-r(>=0)の最小値
#U(0)とR(1)がx+y(2)が一緒:(y-x)のr-u(>=0)の最小値
#L(2)とD(3)がx+y(2)が一緒:(y-x)のd-l(>=0)の最小値
#U(0)とL(2)がy-x(3)が一緒:(y+x)のl-u(>=0)の最小値
#R(1)とD(3)がy-x(3)が一緒:(y+x)のd-r(>=0)の最小値
ans = min(
    calc(cnt[0][0], cnt[3][0]), calc(cnt[1][1], cnt[2][1]),
    calc(cnt[0][2], cnt[1][2]), calc(cnt[2][2], cnt[3][2]),
    calc(cnt[0][3], cnt[2][3]), calc(cnt[1][3], cnt[3][3]))
print('SAFE' if ans == INF else ans * 5)

Buggy python submission (verdict: Runtime Error):
import collections
import itertools
N = int(input())
#cnt[URLD][x y y+x y-x][value]=set()
cnt = [[collections.defaultdict(set) for _ in range(4)] for _ in range(4)]
for _ in range(N):
    x, y, u = input().split()
    x = int(x)
    y = int(y)
    p = y + x
    q = y - x
    i = 'URLD'.index(u)
    cnt[i][0][x].add(y)
    cnt[i][1][y].add(x)
    cnt[i][2][p].add(q)
    cnt[i][3][q].add(p)

INF = float('inf')


def calc(up, down):
    ret = [INF]
    for c in up.keys() & down.keys():
        ua = sorted(up[c])
        da = sorted(down[c])
        i = j = 0
        while i < len(ua):
            while j < len(da):
                if ua[i] > da[j]:
                    j += 1
                else:
                    ret += [da[i] - ua[i]]
                    break
            i += 1
    return min(ret)


#U(0)とD(3)がx(0)が一緒:d-u(>=0)の最小値
#R(1)とL(2)がy(1)が一緒:l-r(>=0)の最小値
#U(0)とR(1)がx+y(2)が一緒:(y-x)のr-u(>=0)の最小値
#L(2)とD(3)がx+y(2)が一緒:(y-x)のd-l(>=0)の最小値
#U(0)とL(2)がy-x(3)が一緒:(y+x)のl-u(>=0)の最小値
#R(1)とD(3)がy-x(3)が一緒:(y+x)のd-r(>=0)の最小値
ans = min(
    calc(cnt[0][0], cnt[3][0]), calc(cnt[1][1], cnt[2][1]),
    calc(cnt[0][2], cnt[1][2]), calc(cnt[2][2], cnt[3][2]),
    calc(cnt[0][3], cnt[2][3]), calc(cnt[1][3], cnt[3][3]))
print('SAFE' if ans == INF else ans * 5)


Fixed submission:
import collections
import itertools
N = int(input())
#cnt[URLD][x y y+x y-x][value]=set()
cnt = [[collections.defaultdict(set) for _ in range(4)] for _ in range(4)]
for _ in range(N):
    x, y, u = input().split()
    x = int(x)
    y = int(y)
    p = y + x
    q = y - x
    i = 'URLD'.index(u)
    cnt[i][0][x].add(y)
    cnt[i][1][y].add(x)
    cnt[i][2][p].add(q)
    cnt[i][3][q].add(p)

INF = float('inf')


def calc(up, down):
    ret = [INF]
    for c in up.keys() & down.keys():
        ua = sorted(up[c])
        da = sorted(down[c])
        i = j = 0
        for i in range(len(ua)):
            for j in range(j, len(da)):
                if ua[i] < da[j]:
                    ret += [da[j] - ua[i]]
                    break
            i += 1
    return min(ret)


#U(0)とD(3)がx(0)が一緒:d-u(>=0)の最小値
#R(1)とL(2)がy(1)が一緒:l-r(>=0)の最小値
#U(0)とR(1)がx+y(2)が一緒:(y-x)のr-u(>=0)の最小値
#L(2)とD(3)がx+y(2)が一緒:(y-x)のd-l(>=0)の最小値
#U(0)とL(2)がy-x(3)が一緒:(y+x)のl-u(>=0)の最小値
#R(1)とD(3)がy-x(3)が一緒:(y+x)のd-r(>=0)の最小値
ans = min(
    calc(cnt[0][0], cnt[3][0]), calc(cnt[1][1], cnt[2][1]),
    calc(cnt[0][2], cnt[1][2]), calc(cnt[2][2], cnt[3][2]),
    calc(cnt[0][3], cnt[2][3]), calc(cnt[1][3], cnt[3][3]))
print('SAFE' if ans == INF else ans * 5)

Buggy python submission (verdict: Time Limit Exceeded):
import collections
import itertools
N = int(input())
#cnt[UDLR][x y x+y x-y][value]=set()
cnt = [[collections.defaultdict(set) for _ in range(4)] for _ in range(4)]
for _ in range(N):
    x, y, u = input().split()
    x = int(x)
    y = int(y)
    p = y + x
    q = y - x
    i = 'UDLR'.index(u)
    cnt[i][0][x].add(y)
    cnt[i][1][y].add(x)
    cnt[i][2][p].add(q)
    cnt[i][3][q].add(p)

INF = float('inf')


def calc(up, down):
    cand = up.keys() & down.keys()
    ans = min(
        [INF] +
        [v2 - v1 for c in cand for v1 in up[c] for v2 in down[c] if v2 >= v1])
    return ans


#U(0)とD(1)がx(0)が一緒:d-u(>=0)の最小値
#R(3)とL(2)がy(1)が一緒:l-r(>=0)の最小値
#U(0)とR(3)がx+y(2)が一緒:(y-x)のr-u(>=0)の最小値
#L(2)とD(1)がx+y(2)が一緒:(y-x)のd-l(>=0)の最小値
#U(0)とL(2)がy-x(3)が一緒:(y+x)のl-u(>=0)の最小値
#R(3)とD(1)がy-x(3)が一緒:(y+x)のd-r(>=0)の最小値
ans = min(
    calc(cnt[0][0], cnt[1][0]), calc(cnt[3][1], cnt[2][1]),
    calc(cnt[0][2], cnt[3][2]), calc(cnt[2][2], cnt[1][2]),
    calc(cnt[0][3], cnt[2][3]), calc(cnt[3][3], cnt[1][3]))

print('SAFE' if ans == INF else ans * 5)


Fixed submission:
import collections
import itertools
N = int(input())
#cnt[URLD][x y y+x y-x][value]=set()
cnt = [[collections.defaultdict(set) for _ in range(4)] for _ in range(4)]
for _ in range(N):
    x, y, u = input().split()
    x = int(x)
    y = int(y)
    p = y + x
    q = y - x
    i = 'URLD'.index(u)
    cnt[i][0][x].add(y)
    cnt[i][1][y].add(x)
    cnt[i][2][p].add(q)
    cnt[i][3][q].add(p)

INF = float('inf')


def calc(up, down):
    ret = [INF]
    for c in up.keys() & down.keys():
        ua = sorted(up[c])
        da = sorted(down[c])
        i = j = 0
        for i in range(len(ua)):
            for j in range(j, len(da)):
                if ua[i] < da[j]:
                    ret += [da[j] - ua[i]]
                    break
            i += 1
    return min(ret)


#U(0)とD(3)がx(0)が一緒:d-u(>=0)の最小値
#R(1)とL(2)がy(1)が一緒:l-r(>=0)の最小値
#U(0)とR(1)がx+y(2)が一緒:(y-x)のr-u(>=0)の最小値
#L(2)とD(3)がx+y(2)が一緒:(y-x)のd-l(>=0)の最小値
#U(0)とL(2)がy-x(3)が一緒:(y+x)のl-u(>=0)の最小値
#R(1)とD(3)がy-x(3)が一緒:(y+x)のd-r(>=0)の最小値
ans = min(
    calc(cnt[0][0], cnt[3][0]), calc(cnt[1][1], cnt[2][1]),
    calc(cnt[0][2], cnt[1][2]), calc(cnt[2][2], cnt[3][2]),
    calc(cnt[0][3], cnt[2][3]), calc(cnt[1][3], cnt[3][3]))
print('SAFE' if ans == INF else ans * 5)

Buggy python submission (verdict: Time Limit Exceeded):
import collections
import itertools
N = int(input())
#cnt[UDLR][x y x+y x-y][value]=set()
#U(0)とD(1)がx(0)が一緒:d-u(>=0)の最小値
#L(2)とR(3)がy(1)が一緒:l-r(>=0)の最小値
#UとRがx+y(2)が一緒:(x-y)のu-r(>=0)の最小値
#LとDがx+y(2)が一緒:(x-y)のl-d(>=0)の最小値
#UとLがx-y(3)が一緒:(x+y)の(l-u)(>=0)の最小値
#RとDがx-y(3)が一緒:(x+y)の(d-r)(>=0)の最小値
cnt = [[collections.defaultdict(set) for _ in range(4)] for _ in range(4)]
for _ in range(N):
    x, y, u = input().split()
    x = int(x)
    y = int(y)
    p = x + y
    q = x - y
    if u == 'U':
        i = 0
    elif u == 'D':
        i = 1
    elif u == 'L':
        i = 2
    else:
        i = 3
    cnt[i][0][x].add(y)
    cnt[i][1][y].add(x)
    cnt[i][2][p].add(q)
    cnt[i][3][q].add(p)
ans = 10**10
for v in cnt[0][0]:
    ans = min([ans] + [
        d - u
        for u, d in itertools.product(cnt[0][0][v], cnt[1][0][v]) if d >= u
    ])
for v in cnt[2][1]:
    ans = min([ans] + [
        l - r
        for l, r in itertools.product(cnt[2][1][v], cnt[3][1][v]) if l >= r
    ])
for v in cnt[0][2]:
    ans = min([ans] + [
        u - r
        for u, r in itertools.product(cnt[0][2][v], cnt[3][2][v]) if u >= r
    ])
for v in cnt[2][2]:
    ans = min([ans] + [
        l - d
        for l, d in itertools.product(cnt[2][2][v], cnt[1][2][v]) if l >= d
    ])
for v in cnt[0][3]:
    ans = min([ans] + [
        l - u
        for l, u in itertools.product(cnt[2][3][v], cnt[0][3][v]) if l >= u
    ])
for v in cnt[3][3]:
    ans = min([ans] + [
        d - r
        for r, d in itertools.product(cnt[3][3][v], cnt[1][3][v]) if d >= r
    ])
print('SAFE' if ans == 10**10 else ans * 5)


Fixed submission:
import collections
import itertools
N = int(input())
#cnt[URLD][x y y+x y-x][value]=set()
cnt = [[collections.defaultdict(set) for _ in range(4)] for _ in range(4)]
for _ in range(N):
    x, y, u = input().split()
    x = int(x)
    y = int(y)
    p = y + x
    q = y - x
    i = 'URLD'.index(u)
    cnt[i][0][x].add(y)
    cnt[i][1][y].add(x)
    cnt[i][2][p].add(q)
    cnt[i][3][q].add(p)

INF = float('inf')


def calc(up, down):
    ret = [INF]
    for c in up.keys() & down.keys():
        ua = sorted(up[c])
        da = sorted(down[c])
        i = j = 0
        for i in range(len(ua)):
            for j in range(j, len(da)):
                if ua[i] < da[j]:
                    ret += [da[j] - ua[i]]
                    break
            i += 1
    return min(ret)


#U(0)とD(3)がx(0)が一緒:d-u(>=0)の最小値
#R(1)とL(2)がy(1)が一緒:l-r(>=0)の最小値
#U(0)とR(1)がx+y(2)が一緒:(y-x)のr-u(>=0)の最小値
#L(2)とD(3)がx+y(2)が一緒:(y-x)のd-l(>=0)の最小値
#U(0)とL(2)がy-x(3)が一緒:(y+x)のl-u(>=0)の最小値
#R(1)とD(3)がy-x(3)が一緒:(y+x)のd-r(>=0)の最小値
ans = min(
    calc(cnt[0][0], cnt[3][0]), calc(cnt[1][1], cnt[2][1]),
    calc(cnt[0][2], cnt[1][2]), calc(cnt[2][2], cnt[3][2]),
    calc(cnt[0][3], cnt[2][3]), calc(cnt[1][3], cnt[3][3]))
print('SAFE' if ans == INF else ans * 5)