#include <bits/stdc++.h>
using namespace std;
int n,m;
int ar[1001][1001],dp[1001][1001];
int count_paths(int i,int j){
	if(i<1 || j<1) return 0;
	if(ar[i][j]==1) return 0;
	if(i==1 && j==1) return 1;

	if(dp[i][j]!=-1) return dp[i][j];
	dp[i][j]=count_paths(i-1,j)+count_paths(i,j-1);
    return dp[i][j];
}
int main(){

	scanf("%d %d",&n,&m);
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			dp[i][j]=-1;
			scanf("%d",&ar[i][j]);
		}
	}
	printf("%d",count_paths(n,m));

	return 0;
}