#include<iostream>
using namespace std;
int main(){
    int height;
    cin>>height;
    //check for valid input
    if(height<1||height>26){
        cout<<"Invalid input";
        return 0;
    }
    //print alphabet triangle
    for(i=1;i<=height;i++){
        charletter='A'
    }
    for(int j=1;j<i=;j++){
        cout<<letter;
        letter++;
        
    }
    cout<<endl;
    return 0;
    }
}