#include<iostream>

#include<cmath>

#include<cstdio>

#include<cstring>

using namespace std;

int n,k;

int map1[][];

int remi[],remj[];

int ans;

int cou;

bool judge(int x,int y)

{

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

        if(remj[i]==y)

            return ;

    return ;

}

void dfs(int cur,int hang)

{

    if(cur==k)

    {

        ++ans;

        return;

    }

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

    {

        if(n-i+<k-cur)

            break;

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

            if(map1[i][j]&&judge(i,j))

            {

                remi[cou]=i;

                remj[cou++]=j;

                dfs(cur+,i+);

                --cou;

            }

    }

}

int main()

{

    char c,s[];

    ios::sync_with_stdio(false);

    for(cin>>n>>k;n!=-&&k!=-;cin>>n>>k)

    {

        ans=;

        cou=;

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

        {

            cin>>s;

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

            {

                c=s[j-];

                if(c=='#')

                    map1[i][j]=;

                else

                    map1[i][j]=;

            }

        }

        dfs(,);

        cout<<ans<<endl;

    }

    return ;

}