#include<bits/stdc++.h>
using namespace std;
const int fx[4]={0,1,0,-1},fy[4]={1,0,-1,0};
int n,m;

struct churui{
	int x,y;
};
queue<churui> q;
char a[505][505];
int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			cin>>a[i][j];
		}
	}
	q.push((churui){0,0});
	while(!q.empty()){
		int x=q.front().x;
		int y=q.front().y;
		q.pop();
		for(int i=0;i<=3;i++){
			int tx=x+fx[i],ty=y+fy[i];
			if(tx>=0&&tx<=n+1&&ty>=0&&ty<=m+1&&a[tx][ty]=='0'){
				a[tx][ty]='1';
				q.push((churui){tx,ty});
			}
		}
	}
	int ans=0;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			if(a[i][j]=='0') ans++;
		}
	}
	return 0;
}

/**************************************************************
	Problem: 1913
	User: liangshinan
	Language: C++
	Result: Wrong Answer
****************************************************************/