#include<bits/stdc++.h>
using namespace std;
int n,m,tx[4]={-1,0,1,0},ty[4]={0,-1,0,1},num;
char a[505][505];

void bfs(int x,int y){
	a[x][y]='*';
	for(int i=0;i<4;i++){
		int dx=x+tx[i],dy=y+ty[i];
		if(dx>=0&&dx<=n+1&&dy>=0&&dy<=m+1&&a[dx][dy]!='*') bfs(dx,dy);
	}
}

int main(){
	cin>>n>>m;
	for(int i=1;i<=n;i++)
		for(int j=1;j<=m;j++)
			cin>>a[i][j];
	bfs(0,0);
	for(int i=1;i<=n;i++)
		for(int j=1;j<=m;j++)
			if(a[i][j]=='0') num++;
	cout<<num;
}
/**************************************************************
	Problem: 1913
	User: yanye
	Language: C++
	Result: Accepted
	Time:29 ms
	Memory:2324 kb
****************************************************************/