int main(int argc, char **argv)
{
std::vector<uint32_t> input = {0x01, 0x03, 0x07, 0x23, 0x25, 0x70, 0x80};
auto result = GetFirstCombination(input.begin(), input.end());
std::cout << std::hex;
do {
for (const auto &ele : result)
std::cout << *std::get<1>(ele) << " ";
std::cout << std::endl;
} while (NextCombination(result.begin(), result.end()));
return 0;
}
int main() {
const int N = 4;
char board[N][N+1];
for (int i = 0; i < N; ++i) {
scanf("%s", board[i]);
}
int state = 0;
for (int x = 0; x < N; ++x) {
for (int y = 0; y < N; ++y) {
if (board[x][y] == 'w') {
int p = x * N + y;
state |= (1 << p);
}
}
}
for (int rounds = 0; rounds <= N*N; ++rounds) {
int array[N*N];
for (int i = 0; i < rounds; ++i) {
array[i] = i;
}
do {
int currState = state;
for (int r = 0; r < rounds; ++r) {
int p = array[r];
currState ^= (1 << p);
int x = p / N, y = p % N;
int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};
for (int k = 0; k < 4; ++k) {
int xx = x + dx[k];
int yy = y + dy[k];
if (xx >= 0 && xx < N && yy >= 0 && yy < N) {
int q = xx * N + yy;
currState ^= (1 << q);
}
}
}
if (currState == 0 || ((~currState) & 0xffff) == 0) {
printf("%d\n", rounds);
return 0;
}
} while (NextCombination(array, N*N, rounds));
}
printf("Impossible\n");
return 0;
}
