import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner sc=new Scanner(System.in);
        try{
            int m=sc.nextInt();
            int n=sc.nextInt();
            if(m<=0||n<=0){
                System.out.println("Invalid input");
                return;
            }
            int[][] grid= new int[m][n];
            long[][] dp=new long[m][n];
            
            for(int i=0;i<m;i++){
                for(int j=0;j<n;j++){
                    int val=sc.nextInt();
                    if(val!=0 && val!=1){
                        System.out.println("Invalid input");
                        return;
                    }
                    grid[i][j]=val;
                }
            }
            if(grid[0][0]==1||grid[m-1][n-1]==1){
                System.out.println(0);
                return;
            }
            dp[0][0]=1;
            for(int i=0;i<m;i++){
                for(int j=0;j<n;j++){
                    if(grid[i][j]=1){
                        dp[i][j]=0;
                    }else{
                        if(i>0) dp[i][j]+=dp[i-1][j];
                        if(j>0) dp[i][j]+=dp[i][j-1];
                    }
                }
            }
            System.out.println(dp[m-1][n-1]);
        }catch(Exception e){
            System.out.println("Invalid input");
        }
    }
}