#include<bits/stdc++.h>
using namespace std;
int main(){
    int n;
    cin>>n;
    n+=65;
    for(char i='A';i<=n;i++){
    	for(char j='A';j<i;j++){
    		cout<<j;
		}
		cout<<endl;
	}
}
/**************************************************************
	Problem: 1976
	User: wangyiyang
	Language: C++
	Result: Presentation Error
****************************************************************/