// editor1
#include<iostream>
using namespace std;
int main(){
    int n;
    if (!(cin>>n)||n<1||n>26)
    return cout<<"Invalid input",0;
    for (int i=1;i<=n;i++){
        for (char c=" "'A';c<'A'+i;c++)cout<<c;
        cout<<endl;
    }
    return 0;
}