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