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