标程

#include <iostream>  
#include <vector>  
#include<iomanip>
#include<cstdio>
using namespace std;
const int N = 10;
int n, k;
char g[N][N]; 
bool qs[N];
int fan = 0;
 
void dfs(int x, int cnt) {
	if (cnt == k) {
		fan++; return; 
	}
	if (x >= n) {
		return;  
	}
	
	for (int i = 0; i < n; i++) {
		if (qs[i] == false && g[x][i] == '#') { 
			qs[i] = true;	
			dfs(x + 1, cnt + 1); 
			qs[i] = false;	
		}
	}
	dfs(x + 1, cnt);
}
int main() { 
	while (cin >> n >> k, n > 0 && k > 0) {
		for (int i = 0; i < n; i++) {
			scanf("%s", g[i]);
		}
		fan = 0;
		dfs(0, 0);
		printf("%d\n", fan);
	}
	return 0;
}