#include<iostream>
using namespace std;
int main() {
    int height;
    cin >> height;
    if(height < 1 || height > 26) {
        cout << "Invalid input" << endl;
        return 0;
    }
        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;
}