#include<stdio.h>
int main()
{
	int n;
	scanf("%d", &n);
	int i, j, k;
	for (i = 0; i < n - 1; i++)
	{
		printf("p");
		for (j = 0, k = i; j < 18; j++, k /= 26)
			printf("%c", 'a' + k % 26);
		printf("p\n");
	}
	printf("pengin\n");
	return 0;
}