Buggy python submission (verdict: Time Limit Exceeded):
h, w = map(int, input().split())
grid = ['#' * (h + 2)]
for _ in range(h):
    grid.append('#' + input() + '#')
grid.append('#' * (h + 2))
lgrid = [[0 for _ in range(w+2)] for _ in range(h+2)]
rgrid = [[0 for _ in range(w+2)] for _ in range(h+2)]
dgrid = [[0 for _ in range(w+2)] for _ in range(h+2)]
ugrid = [[0 for _ in range(w+2)] for _ in range(h+2)]
for i in range(1, h+1):
    for j in range(1, w+1):
        if grid[i][j] == '#':
            lgrid[i][j] = 0
            ugrid[i][j] = 0
        else:
            lgrid[i][j] = lgrid[i][j-1] + 1
            ugrid[i][j] = ugrid[i-1][j] + 1
        if grid[i][w+1-j] == '#':
            rgrid[i][w+1-j] = 0
        else:
            rgrid[i][w+1-j] = rgrid[i][w+2-j] + 1
        if grid[h+1-i][j] == '#':
            dgrid[h+1-i][j] = 0
        else:
            dgrid[h+1-i][j] = dgrid[h+2-i][j] + 1        
cnt = 0
for i in range(1, h+1):
    for j in range(1, w+1):
        tmp = lgrid[i][j]+rgrid[i][j]+ugrid[i][j]+dgrid[i][j] - 3
        cnt = max(cnt, tmp)
print(cnt)


Fixed submission:
h, w = map(int, input().split())
grid = ['#' * (h + 2)]
for _ in range(h):
    grid.append('#' + input() + '#')
grid.append('#' * (h + 2))
lgrid = [[0 for _ in range(w+2)] for _ in range(h+2)]
rgrid = [[0 for _ in range(w+2)] for _ in range(h+2)]
dgrid = [[0 for _ in range(w+2)] for _ in range(h+2)]
ugrid = [[0 for _ in range(w+2)] for _ in range(h+2)]
for i in range(1, h+1):
    for j in range(1, w+1):
        if grid[i][j] == '#':
            lgrid[i][j] = 0
            ugrid[i][j] = 0
        else:
            lgrid[i][j] = lgrid[i][j-1] + 1
            ugrid[i][j] = ugrid[i-1][j] + 1
        if grid[i][w+1-j] == '#':
            rgrid[i][w+1-j] = 0
        else:
            rgrid[i][w+1-j] = rgrid[i][w+2-j] + 1
        if grid[h+1-i][j] == '#':
            dgrid[h+1-i][j] = 0
        else:
            dgrid[h+1-i][j] = dgrid[h+2-i][j] + 1        
cnt = 0
for i in range(1, h+1):
    for j in range(1, w+1):
        tmp = lgrid[i][j]+rgrid[i][j]+ugrid[i][j]+dgrid[i][j] - 3
        cnt = max(cnt, tmp)
print(cnt)

Buggy python submission (verdict: Time Limit Exceeded):
h, w = map(int, input().split())
grid = ['#' * (h + 2)]
for _ in range(h):
    grid.append('#' + input() + '#')
grid.append('#' * (h + 2))
lgrid = {(i, 0): 0 for i in range(1, h + 1)}
rgrid = {(i, w+1): 0 for i in range(1, h + 1)}
dgrid = {(h+1, i): 0 for i in range(1, w + 1)}
ugrid = {(0, i): 0 for i in range(1, w + 1)}
for i in range(1, h+1):
    for j in range(1, w+1):
        if grid[i][j] == '#':
            lgrid[(i, j)] = 0
            ugrid[(i, j)] = 0
        else:
            lgrid[(i, j)] = lgrid[(i, j - 1)] + 1
            ugrid[(i, j)] = ugrid[(i-1, j)] + 1
        if grid[i][w+1-j] == '#':
            rgrid[(i, w+1-j)] = 0
        else:
            rgrid[(i, w+1-j)] = rgrid[(i, w+2-j)] + 1
        if grid[h+1-i][j] == '#':
            dgrid[(h+1-i, j)] = 0
        else:
            dgrid[(h+1-i, j)] = dgrid[(h+2-i, j)] + 1        
cnt = 0
for i in range(1, h+1):
    for j in range(1, w+1):
        tmp = lgrid[(i,j)]+rgrid[(i,j)]+ugrid[(i,j)]+dgrid[(i,j)] - 3
        cnt = max(cnt, tmp)
print(cnt)


Fixed submission:
h, w = map(int, input().split())
grid = ['#' * (h + 2)]
for _ in range(h):
    grid.append('#' + input() + '#')
grid.append('#' * (h + 2))
lgrid = [[0 for _ in range(w+2)] for _ in range(h+2)]
rgrid = [[0 for _ in range(w+2)] for _ in range(h+2)]
dgrid = [[0 for _ in range(w+2)] for _ in range(h+2)]
ugrid = [[0 for _ in range(w+2)] for _ in range(h+2)]
for i in range(1, h+1):
    for j in range(1, w+1):
        if grid[i][j] == '#':
            lgrid[i][j] = 0
            ugrid[i][j] = 0
        else:
            lgrid[i][j] = lgrid[i][j-1] + 1
            ugrid[i][j] = ugrid[i-1][j] + 1
        if grid[i][w+1-j] == '#':
            rgrid[i][w+1-j] = 0
        else:
            rgrid[i][w+1-j] = rgrid[i][w+2-j] + 1
        if grid[h+1-i][j] == '#':
            dgrid[h+1-i][j] = 0
        else:
            dgrid[h+1-i][j] = dgrid[h+2-i][j] + 1        
cnt = 0
for i in range(1, h+1):
    for j in range(1, w+1):
        tmp = lgrid[i][j]+rgrid[i][j]+ugrid[i][j]+dgrid[i][j] - 3
        cnt = max(cnt, tmp)
print(cnt)

Buggy python submission (verdict: Runtime Error):
h, w = map(int, input().split())
grid = ['#' * (h + 2)]
for _ in range(h):
    grid.append('#' + input() + '#')
grid.append('#' * (h+2))
def right(cnt, i, j):
    if grid[i][j + 1] == '.':
        cnt = right(cnt+1, i, j + 1)
    return cnt
        
def left(cnt, i, j):
    if grid[i][j - 1] == '.':
        cnt = left(cnt + 1, i, j - 1)
    return cnt
        
def up(cnt, i, j):
    if grid[i + 1][j] == '.':
        cnt = up(cnt + 1, i + 1, j)
    return cnt

def down(cnt, i, j):
    if grid[i - 1][j] == '.':
        cnt = down(cnt + 1, i - 1, j)
    return cnt

cnt = 0
for i in range(h):
    for j in range(w):
        if grid[i][j] == '.':
            tmp = 1
            tmp = right(tmp, i, j)
            tmp = left(tmp, i, j)
            tmp = up(tmp, i, j)
            tmp = down(tmp, i, j)
            cnt = max(cnt, tmp)
print(cnt)



Fixed submission:
h, w = map(int, input().split())
grid = ['#' * (h + 2)]
for _ in range(h):
    grid.append('#' + input() + '#')
grid.append('#' * (h + 2))
lgrid = [[0 for _ in range(w+2)] for _ in range(h+2)]
rgrid = [[0 for _ in range(w+2)] for _ in range(h+2)]
dgrid = [[0 for _ in range(w+2)] for _ in range(h+2)]
ugrid = [[0 for _ in range(w+2)] for _ in range(h+2)]
for i in range(1, h+1):
    for j in range(1, w+1):
        if grid[i][j] == '#':
            lgrid[i][j] = 0
            ugrid[i][j] = 0
        else:
            lgrid[i][j] = lgrid[i][j-1] + 1
            ugrid[i][j] = ugrid[i-1][j] + 1
        if grid[i][w+1-j] == '#':
            rgrid[i][w+1-j] = 0
        else:
            rgrid[i][w+1-j] = rgrid[i][w+2-j] + 1
        if grid[h+1-i][j] == '#':
            dgrid[h+1-i][j] = 0
        else:
            dgrid[h+1-i][j] = dgrid[h+2-i][j] + 1        
cnt = 0
for i in range(1, h+1):
    for j in range(1, w+1):
        tmp = lgrid[i][j]+rgrid[i][j]+ugrid[i][j]+dgrid[i][j] - 3
        cnt = max(cnt, tmp)
print(cnt)