Buggy python submission (verdict: Runtime Error):
import itertools
H, W = [int(_) for _ in input().split()]
S = [input() for _ in range(H)]
A = [[0 for _ in range(W)] for _ in range(H)]
count = {}


def dfs(x, y, p, q):
    if A[x][y] == 1:
        return
    else:
        A[x][y] = 1
        count[p * H + q] = count.get(p * H + q, {})
        count[p * H + q][S[x][y]] = count[p * H + q].get(S[x][y], 0) + 1
        dxy = [[-1, 0], [1, 0], [0, -1], [0, 1]]
        for dx, dy in dxy:
            nx, ny = x + dx, y + dy
            if 0 <= nx < H and 0 <= ny < W:
                if S[x][y] == S[nx][ny]:
                    dfs(nx, ny, nx, ny)
                else:
                    dfs(nx, ny, p, q)


dfs(0, 0, 0, 0)
ans = 0
for i in count:
    ans += count[i].get('#', 0) * count[i].get('.', 0)
print(ans)


Fixed submission:
import itertools
H, W = [int(_) for _ in input().split()]
S = [input() for _ in range(H)]
A = [[0 for _ in range(W)] for _ in range(H)]


def dfs(p, q):
    if A[p][q] == 1:
        return 0
    count = {'#': 0, '.': 0}
    stack = [[p, q]]
    while stack:
        x, y = stack.pop()
        if A[x][y] != 1:
            count[S[x][y]] += 1
            A[x][y] = 1
            dxy = [[-1, 0], [1, 0], [0, -1], [0, 1]]
            for dx, dy in dxy:
                nx, ny = x + dx, y + dy
                if 0 <= nx < H and 0 <= ny < W and S[x][y] != S[nx][ny]:
                    stack += [[nx, ny]]
    return count['#'] * count['.']


print(sum([dfs(i, j) for i, j in itertools.product(range(H), range(W))]))

Buggy python submission (verdict: Runtime Error):
import itertools
H, W = [int(_) for _ in input().split()]
S = [input() for _ in range(H)]
A = [[0 for _ in range(W)] for _ in range(H)]
count = {}


def bfs(x, y, p, q):
    if A[x][y] == 1:
        return
    else:
        A[x][y] = 1
        count[p * H + q] = count.get(p * H + q, {})
        count[p * H + q]['#'] = count[p * H + q].get('#', 0)
        count[p * H + q]['.'] = count[p * H + q].get('.', 0)
        count[p * H + q][S[x][y]] += 1
        dxy = [[-1, 0], [1, 0], [0, -1], [0, 1]]
        for dx, dy in dxy:
            nx, ny = x + dx, y + dy
            if 0 <= nx < H and 0 <= ny < W:
                if S[x][y] != S[nx][ny] and A[nx][ny] == 0:
                    bfs(nx, ny, p, q)


for i, j in itertools.product(range(H), range(W)):
    bfs(i, j, i, j)
ans = 0
if count:
    for i in count:
        ans += count[i].get('#', 0) * count[i].get('.', 0)
print(ans)


Fixed submission:
import itertools
H, W = [int(_) for _ in input().split()]
S = [input() for _ in range(H)]
A = [[0 for _ in range(W)] for _ in range(H)]


def dfs(p, q):
    if A[p][q] == 1:
        return 0
    count = {'#': 0, '.': 0}
    stack = [[p, q]]
    while stack:
        x, y = stack.pop()
        if A[x][y] != 1:
            count[S[x][y]] += 1
            A[x][y] = 1
            dxy = [[-1, 0], [1, 0], [0, -1], [0, 1]]
            for dx, dy in dxy:
                nx, ny = x + dx, y + dy
                if 0 <= nx < H and 0 <= ny < W and S[x][y] != S[nx][ny]:
                    stack += [[nx, ny]]
    return count['#'] * count['.']


print(sum([dfs(i, j) for i, j in itertools.product(range(H), range(W))]))

Buggy python submission (verdict: Runtime Error):
import itertools
H, W = [int(_) for _ in input().split()]
S = [input() for _ in range(H)]
A = [[0 for _ in range(W)] for _ in range(H)]
count = {}


def bfs(x, y, p, q):
    if A[x][y] == 1:
        return
    else:
        A[x][y] = 1
        count[p * H + q] = count.get(p * H + q, {})
        count[p * H + q]['#'] = count[p * H + q].get('#', 0)
        count[p * H + q]['.'] = count[p * H + q].get('.', 0)
        count[p * H + q][S[x][y]] += 1
        dxy = [[-1, 0], [1, 0], [0, -1], [0, 1]]
        for dx, dy in dxy:
            nx, ny = x + dx, y + dy
            if 0 <= nx < H and 0 <= ny < W:
                if S[x][y] != S[nx][ny] and A[nx][ny] == 0:
                    bfs(nx, ny, p, q)


for i, j in itertools.product(range(H), range(W)):
    bfs(i, j, i, j)
ans = 0
for i in count:
    ans += count[i].get('#', 0) * count[i].get('.', 0)
print(ans)


Fixed submission:
import itertools
H, W = [int(_) for _ in input().split()]
S = [input() for _ in range(H)]
A = [[0 for _ in range(W)] for _ in range(H)]


def dfs(p, q):
    if A[p][q] == 1:
        return 0
    count = {'#': 0, '.': 0}
    stack = [[p, q]]
    while stack:
        x, y = stack.pop()
        if A[x][y] != 1:
            count[S[x][y]] += 1
            A[x][y] = 1
            dxy = [[-1, 0], [1, 0], [0, -1], [0, 1]]
            for dx, dy in dxy:
                nx, ny = x + dx, y + dy
                if 0 <= nx < H and 0 <= ny < W and S[x][y] != S[nx][ny]:
                    stack += [[nx, ny]]
    return count['#'] * count['.']


print(sum([dfs(i, j) for i, j in itertools.product(range(H), range(W))]))

Buggy python submission (verdict: Runtime Error):
import itertools
H, W = [int(_) for _ in input().split()]
S = [input() for _ in range(H)]
A = [[0 for _ in range(W)] for _ in range(H)]
count = {}


def bfs(x, y, p, q):
    if A[x][y] == 1:
        return
    else:
        A[x][y] = 1
        count[p * H + q] = count.get(p * H + q, {})
        count[p * H + q]['#'] = count[p * H + q].get('#', 0)
        count[p * H + q]['.'] = count[p * H + q].get('.', 0)
        count[p * H + q][S[x][y]] += 1
        dxy = [[-1, 0], [1, 0], [0, -1], [0, 1]]
        for dx, dy in dxy:
            nx, ny = x + dx, y + dy
            if 0 <= nx < H and 0 <= ny < W:
                if S[x][y] != S[nx][ny] and A[nx][ny] == 0:
                    bfs(nx, ny, p, q)


for i, j in itertools.product(range(H), range(W)):
    bfs(i, j, i, j)
ans = 0
for i in count:
    ans += count[i]['#'] * count[i]['.']
print(ans)


Fixed submission:
import itertools
H, W = [int(_) for _ in input().split()]
S = [input() for _ in range(H)]
A = [[0 for _ in range(W)] for _ in range(H)]


def dfs(p, q):
    if A[p][q] == 1:
        return 0
    count = {'#': 0, '.': 0}
    stack = [[p, q]]
    while stack:
        x, y = stack.pop()
        if A[x][y] != 1:
            count[S[x][y]] += 1
            A[x][y] = 1
            dxy = [[-1, 0], [1, 0], [0, -1], [0, 1]]
            for dx, dy in dxy:
                nx, ny = x + dx, y + dy
                if 0 <= nx < H and 0 <= ny < W and S[x][y] != S[nx][ny]:
                    stack += [[nx, ny]]
    return count['#'] * count['.']


print(sum([dfs(i, j) for i, j in itertools.product(range(H), range(W))]))