#include<bits/stdc++.h>
using namespace std;
int n,m,ans;
char a[501][501];
int fx[4]={0,1,0,-1};
int fy[4]={1,0,-1,0};
void dfs(int x,int y){
//	cout<<x<<" "<<y<<endl;
	for(int i=0;i<=3;i++){
		int tx=fx[i]+x;
		int ty=fy[i]+y;
		if(tx>=1&&tx<=n&&ty>=1&&ty<=m&&a[tx][ty]=='0'){
			a[tx][ty]='*';
			dfs(tx,ty);
		}
	}
	
}
int main(){
    cin>>n>>m;
    for(int i=1;i<=n;i++){
    	for(int j=1;j<=m;j++){
    		cin>>a[i][j];
    	}
    }
    for(int i=1;i<=n;i++){
    	for(int j=1;j<=m;j++){
    		if((i==1||j==1||i==n||j==m)&&a[i][j]=='0'){
    			a[i][j]='*';
    			dfs(i,j);
    		}
    	}
    }
    for(int i=1;i<=n;i++){
    	for(int j=1;j<=m;j++){
    		if(a[i][j]=='0'){
    			ans++;
    		}
    	}
    }
    cout<<ans;
	return 0;
}

/**************************************************************
	Problem: 1913
	User: chenjingqi
	Language: C++
	Result: Accepted
	Time:98 ms
	Memory:2320 kb
****************************************************************/