/*
TASK:apple
LANG:C
*/

#include <stdio.h>

int a[69][69];

int main(int argc, char* argv[])
{
    int i, j;
    int m, n;
    long max = 0;
   
    scanf("%d %d", &m, &n);
    for(i = 0; i < m; i++) for(j = 0; j < n; j++) scanf("%d", &(a[i][j]));

    max += a[0][0];
    a[0][0] = 0;
    max += a[m - 1][j - 1];
    a[m - 1][j - 1] = 0;

    return 0;
}
