import copy
n = int(input())
w_list = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j']
ans_list = []
for i in range(n):
    temp_word = []
    word = []
    for j in range(n):
        if temp_word == []:
            w = copy.deepcopy(w_list[0:i+1])
            temp_word.extend(w)
        aaa = temp_word.pop(0)
        word.append(aaa)
    ans_list.append(''.join(word))
for s in ans_list:
    print(s)