// editor5
#include <iostream>
using namespace std;
int main(){
    int n;
     cin>>n;
     if (n<=26){
     for (int i=1;i<=n;++i){
         for (int j=0;j<i;++j){
             char letter ="A"+j; 
             cout<<letter;
         }
         cout<<endl;
     }
}
}