#include<stdio.h>
int main()
{
    int m,n;
    scanf("%d",&m);
    scanf("%d",&m);
    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,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<=bootom)
        {
            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++;
            }
        }
    }
}