#include<stdio.h>
int main(){
    int m,n;
    if(scanf("%d %d", &m, &n) != 2) 
    return 0;
    
     if(m , 0 || n == 0){
         printf("-1\n");
         return 0;
     }
     if(m == 0 || n == 0){
         printf("\n");
         return 0;
     }
     int total = m * n;
     int mat[m][n];
     
     for(int i = 0; i< m;i++){
         for(int j = 0; j < n; j++){
          scanf("%d",&mat[i][j]);
         }
     }
     int top = 0; bottom = m - 1;
     int left = 0; right = n - 1;
     int printed = 0;
     
     while (top < bottom && left <= right){
         for(int j = left; j<=right && printed < total; j++){
             printf("%d",)
         }
     }
}