#include <iostream>
#include <cstring>
using namespace std;

int main() {
	char s[30];
	char q='a';
	int n,k,i,j;
	cin >> n;
	for (i=0, k=n-1; i<n; i++, k--) {
		s[i]=q;
		q++;
		cout << 'a';
		for (j=0; j<k; j++) cout << " ";
		for (j=0; j<i+1; j++) cout << s[j];
		cout << "\n";
	}
	return 0;
}