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#include<cstdio>
#include<set>
using namespace std;

char t[3005][3005];
int n;

bool ok(int x, int y){
	return (0<=x && x<n && 0<=y && y<n && t[x][y]=='.');
}

int wyn=0;

void licz(set<pair<int,int> > r, int m){
	if(m<=0){
		wyn++;
		return;
	}

	set<pair<int,int> > rec;

	while(!r.empty()){
		int i=r.begin()->first;
		int j=r.begin()->second;

		rec.insert(make_pair(i,j));

		r.erase(r.begin());

		if(ok(i,j)){
			set<pair<int,int> > s=r;

			t[i][j]='#';
			s.erase(make_pair(i,j));

			if(t[i][j]=='#'){
				if(ok(i-1,j))
					s.insert(make_pair(i-1,j));

				if(ok(i+1,j))
					s.insert(make_pair(i+1,j));

				if(ok(i,j-1))
					s.insert(make_pair(i,j-1));

				if(ok(i,j+1))
					s.insert(make_pair(i,j+1));
			}

			licz(s,m-1);
		}
	}

	while(!rec.empty()){
		int i=rec.begin()->first;
		int j=rec.begin()->second;

		t[i][j]='.';

		rec.erase(rec.begin());
	}

	return;
}

int main(void){
	int m;

	scanf("%d%d",&n,&m);

	for(int i=0;i<n;i++)
		scanf("%s",t[i]);

	set<pair<int,int> > s;
	for(int i=0;i<n;i++)
		for(int j=0;j<n;j++)
			if(t[i][j]=='#'){
				if(ok(i-1,j))
					s.insert(make_pair(i-1,j));

				if(ok(i+1,j))
					s.insert(make_pair(i+1,j));

				if(ok(i,j-1))
					s.insert(make_pair(i,j-1));

				if(ok(i,j+1))
					s.insert(make_pair(i,j+1));
			}

	licz(s,m);

	printf("%d\n",wyn);
	return 0;
}