#include<bits/stdc++.h>
using namespace std;
int a[20][20];
int n;
int main(){
	cin>>n;
	for(int i=1;i<=n;i++){
		int x=i;
		for(int j=1;j<=n;j++){
			if(i+j<=n+1)a[i][j]=i+j-1;
			else a[i][j]=2*n-(i+j)+1;
		}
	}
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			cout<<setw(3)<<(char)(a[i][j]+64);
			
		}
		cout<<endl;
	}


	return 0;
}

/**************************************************************
	Problem: 1194
	User: wuzihang
	Language: C++
	Result: Wrong Answer
****************************************************************/