#include <stdio.h>
int main () {
    int m,n;
    scanf ("%d%d",&m,&n);
    int matrix [m][n];
    for (int i=0;i<m;i++){
    for (int j=0;j<n;j++){
        scanf("%d",&matrix[i][j]);
    }
    }
    int sum=0
    for (int i=0;i<m;i++){
        for (int j=0;j<n;j++ ){
            if (i==0||i==m-1||j==0||j==n-1){
                sum +=matrix[i][j;
                ]
            }
        }
    }
    printf ("%d",sum);
    return 0;
}