#include<iostream>
using namespace std;
char map[8][8];
bool visit_row[8],visit_column[8];
int n,k,sum;
void search(int k,int begin)
{
	int i,j;
	for(i=begin;i<n-k+1;i++)
	{
		for(j=0;j<n;j++)
		{
			if(map[i][j]=='#'&&!visit_row[i]&&!visit_column[j])
			{
				visit_row[i]=true;
				visit_column[j]=true;
				if(k-1==0){
					sum++;
				}
				else{
					search(k-1,i+1);
				}
				visit_row[i]=false;
				visit_column[j]=false;
			}
		}
	}
	return ;
}
int main(void)
{
	int i,j;
	while(cin>>n>>k&&!(n==-1&&k==-1))
	{
		sum=0;
		memset(visit_row,false,sizeof(visit_row));
		memset(visit_column,false,sizeof(visit_column));
		for(i=0;i<n;i++)
			for(j=0;j<n;j++)
				cin>>map[i][j];
		search(k,0);
		cout<<sum<<endl;
	}
	return 0;
}