#include<iostream>

 #include<cstdio>

 #include<string>

 #include<vector>

 #include<cstring>

 using namespace std;

 struct node

 {

     int x;

     int y;

 };

 int n, k, l, ans;

 bool w[], h[];

 vector<node>dot;

 void bfs(int a, int b)

 {

     if(a==k+)

     {

         ans++;

         return;

     }

     for(int i = b; i < l; i++)

     {

         if(w[dot[i].x] || h[dot[i].y])    continue;

         else

         {

             w[dot[i].x] = h[dot[i].y] = true;

             bfs(a+, i+);

             w[dot[i].x] = h[dot[i].y] = false;

         }

     }

     return;

 }

 int main()

 {

 //    freopen("in.in","r",stdin);

     string c;

     node tmp;

     while(cin>>n>>k)

     {

         dot.clear();

         memset(w,,sizeof(w));

         memset(h,,sizeof(h));

         if(n==-)    break;

         for(int i = ; i <= n; i++)

         {

             cin>>c;

             for(int j = ; j <= n; j++)

             {

                 if(c[j-]=='#')

                 {

                     tmp.x = i;

                     tmp.y = j;

                     dot.push_back(tmp);

                 }

             }

         }

         l = dot.size();

         ans = ;

         bfs(,);

         cout<<ans<<endl;

     }

     return ;

 }