Buggy python submission (verdict: Runtime Error):
from collections import deque
h,w=list(map(int, input().split()))
s = [input() for _ in range(h)]

water=[[0]*w for _ in range(w)]
water[0][0]=1
a_index=[]
a_column=[]
a_index.append(0)
a_column.append(0)
b=[]
count=0

for i in range(h):
    for j in range(w):
        if s[i][j] == '#':
            water[i][j]=3000
            count+=1
while water[h-1][w-1]==0:
    for i,j in zip(a_index,a_column):
        if water[i][j]==1:
            if i>0:
                if water[i-1][j]==0:
                    water[i-1][j]+=1
                    b.insert(0,[i-1,j])
            if i<h-1:
                if water[i+1][j]==0:
                    water[i+1][j]+=1
                    b.insert(0,[i+1,j])
            if j>0:
                if water[i][j-1]==0:
                    water[i][j-1]+=1
                    b.insert(0,[i,j-1])
            if j<w-1:
                if water[i][j+1]==0:
                    water[i][j+1]+=1
                    b.insert(0,[i,j+1])
        water[i][j]+=1
    a_index+=[x[0] for x in b]
    a_column+=[x[1] for x in b]

    if not b:
        print(-1)
        exit()
    b=[]

print(h*w-water[0][0]-count)


Fixed submission:
from collections import deque
h,w=list(map(int, input().split()))
s = [input() for _ in range(h)]

water=[[0]*w for _ in range(h)]
water[0][0]=1
a_index=[]
a_column=[]
a_index.append(0)
a_column.append(0)
b=[]
count=0

for i in range(h):
    for j in range(w):
        if s[i][j] == '#':
            water[i][j]=3000
            count+=1
while water[h-1][w-1]==0:
    for i,j in zip(a_index,a_column):
        if water[i][j]==1:
            if i>0:
                if water[i-1][j]==0:
                    water[i-1][j]+=1
                    b.insert(0,[i-1,j])
            if i<h-1:
                if water[i+1][j]==0:
                    water[i+1][j]+=1
                    b.insert(0,[i+1,j])
            if j>0:
                if water[i][j-1]==0:
                    water[i][j-1]+=1
                    b.insert(0,[i,j-1])
            if j<w-1:
                if water[i][j+1]==0:
                    water[i][j+1]+=1
                    b.insert(0,[i,j+1])
        water[i][j]+=1

    a_index+=[x[0] for x in b]
    a_column+=[x[1] for x in b]

    if not b:
        print(-1)
        exit()
    b=[]

print(h*w-water[0][0]-count)

Buggy python submission (verdict: Runtime Error):
from collections import deque
h,w=list(map(int, input().split()))
s = [input() for _ in range(h)]

water=[[0]*w for _ in range(w)]
water[0][0]=1
a_index=[]
a_column=[]
a_index.append(0)
a_column.append(0)
b=[]
count=0
flag=True
for i in range(h):
    for j in range(w):
        if s[i][j] == '#':
            water[i][j]=3000
            count+=1
while water[h-1][w-1]==0:
    for i,j in zip(a_index,a_column):
        if water[i][j]==1:
            if i>0:
                if water[i-1][j]==0:
                    water[i-1][j]+=1
                    b.insert(0,[i-1,j])
            if i<h-1:
                if water[i+1][j]==0:
                    water[i+1][j]+=1
                    b.insert(0,[i+1,j])
            if j>0:
                if water[i][j-1]==0:
                    water[i][j-1]+=1
                    b.insert(0,[i,j-1])
            if j<w-1:
                if water[i][j+1]==0:
                    water[i][j+1]+=1
                    b.insert(0,[i,j+1])
        water[i][j]+=1
    a_index+=[x[0] for x in b]
    a_column+=[x[1] for x in b]

    if not b:
        flag=False
        break
    b=[]

if flag:
    print(h*w-water[0][0]-count)
else:
    print(-1)


Fixed submission:
from collections import deque
h,w=list(map(int, input().split()))
s = [input() for _ in range(h)]

water=[[0]*w for _ in range(h)]
water[0][0]=1
a_index=[]
a_column=[]
a_index.append(0)
a_column.append(0)
b=[]
count=0

for i in range(h):
    for j in range(w):
        if s[i][j] == '#':
            water[i][j]=3000
            count+=1
while water[h-1][w-1]==0:
    for i,j in zip(a_index,a_column):
        if water[i][j]==1:
            if i>0:
                if water[i-1][j]==0:
                    water[i-1][j]+=1
                    b.insert(0,[i-1,j])
            if i<h-1:
                if water[i+1][j]==0:
                    water[i+1][j]+=1
                    b.insert(0,[i+1,j])
            if j>0:
                if water[i][j-1]==0:
                    water[i][j-1]+=1
                    b.insert(0,[i,j-1])
            if j<w-1:
                if water[i][j+1]==0:
                    water[i][j+1]+=1
                    b.insert(0,[i,j+1])
        water[i][j]+=1

    a_index+=[x[0] for x in b]
    a_column+=[x[1] for x in b]

    if not b:
        print(-1)
        exit()
    b=[]

print(h*w-water[0][0]-count)

Buggy python submission (verdict: Runtime Error):
from collections import deque
h,w=list(map(int, input().split()))
s = [input() for _ in range(h)]

water=[[0]*w for _ in range(w)]
water[0][0]=1
a_index=[]
a_column=[]
a_index.append(0)
a_column.append(0)
b=[]
count=0
flag=True
for i in range(h):
    for j in range(w):
        if s[j][i] == '#':
            water[i][j]=3000
            count+=1
while water[h-1][w-1]==0:
    for i,j in zip(a_index,a_column):
        if water[i][j]==1:
            if i>0:
                if water[i-1][j]==0:
                    water[i-1][j]+=1
                    b.insert(0,[i-1,j])
            if i<h-1:
                if water[i+1][j]==0:
                    water[i+1][j]+=1
                    b.insert(0,[i+1,j])
            if j>0:
                if water[i][j-1]==0:
                    water[i][j-1]+=1
                    b.insert(0,[i,j-1])
            if j<w-1:
                if water[i][j+1]==0:
                    water[i][j+1]+=1
                    b.insert(0,[i,j+1])
        water[i][j]+=1
    a_index+=[x[0] for x in b]
    a_column+=[x[1] for x in b]

    if not b:
        flag=False
        break
    b=[]

if flag:
    print(h*w-water[0][0]-count)
else:
    print(-1)


Fixed submission:
from collections import deque
h,w=list(map(int, input().split()))
s = [input() for _ in range(h)]

water=[[0]*w for _ in range(h)]
water[0][0]=1
a_index=[]
a_column=[]
a_index.append(0)
a_column.append(0)
b=[]
count=0

for i in range(h):
    for j in range(w):
        if s[i][j] == '#':
            water[i][j]=3000
            count+=1
while water[h-1][w-1]==0:
    for i,j in zip(a_index,a_column):
        if water[i][j]==1:
            if i>0:
                if water[i-1][j]==0:
                    water[i-1][j]+=1
                    b.insert(0,[i-1,j])
            if i<h-1:
                if water[i+1][j]==0:
                    water[i+1][j]+=1
                    b.insert(0,[i+1,j])
            if j>0:
                if water[i][j-1]==0:
                    water[i][j-1]+=1
                    b.insert(0,[i,j-1])
            if j<w-1:
                if water[i][j+1]==0:
                    water[i][j+1]+=1
                    b.insert(0,[i,j+1])
        water[i][j]+=1

    a_index+=[x[0] for x in b]
    a_column+=[x[1] for x in b]

    if not b:
        print(-1)
        exit()
    b=[]

print(h*w-water[0][0]-count)

Buggy python submission (verdict: Runtime Error):
from collections import deque
h,w=list(map(int, input().split()))
s = [input() for _ in range(h)]

water=[[0]*w for _ in range(w)]
water[0][0]=0
a_index=[]
a_column=[]
a_index.append(0)
a_column.append(0)
b=[]
count=0
flag=True
for i in range(h):
    for j in range(w):
        if s[i][j] == '#':
            water[i][j]=3000
            count+=1
while water[h-1][w-1]==0:
    for i,j in zip(a_index,a_column):
        if water[i][j]==1:
            if i>0:
                if water[i-1][j]==0:
                    water[i-1][j]+=1
                    b.insert(0,[i-1,j])
            if i<h-1:
                if water[i+1][j]==0:
                    water[i+1][j]+=1
                    b.insert(0,[i+1,j])
            if j>0:
                if water[i][j-1]==0:
                    water[i][j-1]+=1
                    b.insert(0,[i,j-1])
            if j<w-1:
                if water[i][j+1]==0:
                    water[i][j+1]+=1
                    b.insert(0,[i,j+1])
        water[i][j]+=1
    a_index+=[x[0] for x in b]
    a_column+=[x[1] for x in b]
    if not b:
        flag=False
        break
    b=[]
if flag:
    print(h*w-water[0][0]-count)
else:
    print(-1)

Fixed submission:
from collections import deque
h,w=list(map(int, input().split()))
s = [input() for _ in range(h)]

water=[[0]*w for _ in range(h)]
water[0][0]=1
a_index=[]
a_column=[]
a_index.append(0)
a_column.append(0)
b=[]
count=0

for i in range(h):
    for j in range(w):
        if s[i][j] == '#':
            water[i][j]=3000
            count+=1
while water[h-1][w-1]==0:
    for i,j in zip(a_index,a_column):
        if water[i][j]==1:
            if i>0:
                if water[i-1][j]==0:
                    water[i-1][j]+=1
                    b.insert(0,[i-1,j])
            if i<h-1:
                if water[i+1][j]==0:
                    water[i+1][j]+=1
                    b.insert(0,[i+1,j])
            if j>0:
                if water[i][j-1]==0:
                    water[i][j-1]+=1
                    b.insert(0,[i,j-1])
            if j<w-1:
                if water[i][j+1]==0:
                    water[i][j+1]+=1
                    b.insert(0,[i,j+1])
        water[i][j]+=1

    a_index+=[x[0] for x in b]
    a_column+=[x[1] for x in b]

    if not b:
        print(-1)
        exit()
    b=[]

print(h*w-water[0][0]-count)

Buggy python submission (verdict: Runtime Error):
from collections import deque
h,w=list(map(int, input().split()))
s = [input() for _ in range(h)]

water=[[0]*w for _ in range(w)]
water[0][0]=0
a_index=[]
a_column=[]
a_index.append(0)
a_column.append(0)
b=[]
count=0
for i in range(h):
    for j in range(w):
        if s[i][j] == '#':
            water[i][j]=3000
            count+=1
while water[h-1][w-1]==0:
    for i,j in zip(a_index,a_column):
        if water[i][j]==1:
            if i>0:
                if water[i-1][j]==0:
                    water[i-1][j]+=1
                    b.insert(0,[i-1,j])
            if i<h-1:
                if water[i+1][j]==0:
                    water[i+1][j]+=1
                    b.insert(0,[i+1,j])
            if j>0:
                if water[i][j-1]==0:
                    water[i][j-1]+=1
                    b.insert(0,[i,j-1])
            if j<w-1:
                if water[i][j+1]==0:
                    water[i][j+1]+=1
                    b.insert(0,[i,j+1])
        water[i][j]+=1
    a_index+=[x[0] for x in b]
    a_column+=[x[1] for x in b]
    b=[]

print(h*w-water[0][0]-count)


Fixed submission:
from collections import deque
h,w=list(map(int, input().split()))
s = [input() for _ in range(h)]

water=[[0]*w for _ in range(h)]
water[0][0]=1
a_index=[]
a_column=[]
a_index.append(0)
a_column.append(0)
b=[]
count=0

for i in range(h):
    for j in range(w):
        if s[i][j] == '#':
            water[i][j]=3000
            count+=1
while water[h-1][w-1]==0:
    for i,j in zip(a_index,a_column):
        if water[i][j]==1:
            if i>0:
                if water[i-1][j]==0:
                    water[i-1][j]+=1
                    b.insert(0,[i-1,j])
            if i<h-1:
                if water[i+1][j]==0:
                    water[i+1][j]+=1
                    b.insert(0,[i+1,j])
            if j>0:
                if water[i][j-1]==0:
                    water[i][j-1]+=1
                    b.insert(0,[i,j-1])
            if j<w-1:
                if water[i][j+1]==0:
                    water[i][j+1]+=1
                    b.insert(0,[i,j+1])
        water[i][j]+=1

    a_index+=[x[0] for x in b]
    a_column+=[x[1] for x in b]

    if not b:
        print(-1)
        exit()
    b=[]

print(h*w-water[0][0]-count)