#include<iostream>
#include <algorithm>
#include<string>
#include <bitset>
#include <vector>
using namespace std;
int main()
{
	//int a = 0, b = 0, c = 0, d = 0, e = 0, f = 0, g = 0, h = 0, ans = 0;
	long a = 0, b = 0, c = 0, d = 0, e = 0, f = 0, g = 0, h = 0, i = 0, j = 0, k = 0, l = 0, ans = 0;
	//cout << LONG_MAX << endl;
	//string s[1001];
	char buffer[33];

	cin >> a;
	b = 0;
						if (a == 1)
						{
							cout << "an" << endl;
							return 0;
						}
	//for ( b = 0; b < a; b++)
	{
		for (c = 97; c < 123; c++)
		{
			for (d = 97; d < 123; d++)
			{
				for (e = 97; e < 123; e++)
				{
					for (f = 97; f < 123; f++)
					{
						printf("a%c%c%c%ca\n", c, d, e, f);
						b++;
						if (b == a-1)
						{
							cout << "an" << endl;
							return 0;
						}
					}
				}
			}
		}
		//c = 'a';
		//c += b;
		//cout << "a" << c << endl;
	}





	//cout << ans << endl;
	return 0;
}