#include<iostream>
#include <cstring>
using namespace std;
int main(){
    int n,i,j,k,c;
    char x;
    cin>>n;
    c=1;
    x='A';
    for(int i=1;i<=n;i++){
        for(int j=1;j<=c;j++){
        	cout<<x;
		}
		cout<<endl;
		c+=1;
		x=int(x)+1;
		x=char(x);
    }
    return 0;
}


/**************************************************************
	Problem: 1977
	User: xuanhua
	Language: C++
	Result: Accepted
	Time:13 ms
	Memory:2072 kb
****************************************************************/