#include <iostream>#include <cstdio>#include <cstdlib>#include <cstring>using namespace std;#define maxn 10bool row[maxn], col[maxn];bool map[maxn][maxn];int ans, n, m;void input(){ char ch; memset(map, 0, sizeof(map)); getchar(); for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { ch = getchar(); if (ch == '#') map[i][j] = true; else map[i][j] = false; } getchar(); }}void dfs(int pos, int a){ if (a == m) { ans++; return; } while (pos < n * n) { int x = pos / n; int y = pos % n; if (map[x][y] && !row[x] && !col[y]) { row[x] = col[y] = true; dfs(pos + 1, a + 1); row[x] = col[y] = false; } pos++; }}int main(){ while (scanf("%d%d", &n, &m), !(n == -1 && m == -1)) { input(); memset(row, 0, sizeof(row)); memset(col, 0, sizeof(col)); ans = 0; dfs(0, 0); printf("%dn", ans); } return 0;}
