#include <bits/stdc++.h>
using namespace std;
int main()
{

    char a[20][20]={0};
    int n;
    cin >>n;
    for(int i=0;i<n;i++)
    {
        for(int j =0;j<=i;j++)
        {
    
            a[j][i-j] = ('A'+i);
            if(n-1-j + n-1-i+j != n-1)
            {
                a[n-1-j][n-1-i+j] = 'A'+(63+n-'A'-i);
            }

        }
        
    }

    for(int i=0;i<n;i++)
    {
        for(int j =0;j<n;j++)
        {   
            cout<<setw(3)<<a[i][j];
        }
        cout <<endl;
    }
    
    return 0;
}


/**************************************************************
	Problem: 1194
	User: mariooo
	Language: C++
	Result: Accepted
	Time:10 ms
	Memory:2072 kb
****************************************************************/