#include<iostream>
using namespace std;
int main(){
    int height;
    cin>>height ;
    if (height<1||height >26){
        cout<<"invalid input";
    
        return 0;
    }
    for(int i=1;i<=height;i++){
        char letter=  'A'  ;
        for(int j=1;j<=i;j++){
            cout<< letter ;
            letter++;
        }
        cout<< \t endl;
    }
    
    
}