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