#include<iostream>
using namespace std;
int main() {
    int height;
    cin>>height;
    if(height<1||height>26) {
        cout<<"Inavild input";
        return 0;
    }
    for(int i=1;1<=height;i++) {
        for(int j=0;j<i;j++) {
            cout<<char('A'+j);
            if(j<i-1) {
                cout<<" ";
            }
        }
        cout<<endl;
    }
    return 0;
}