import itertools

n = input()
n = int(n)

num = [i for i in range(n)]
pairs = [i for i in itertools.combinations(num, 2)]

hoge = len(pairs) + 1
for i in range(1, hoge):
    comb = itertools.combinations(pairs, i)

    dup_check = set()
    for c in comb:
        c_list = list(c)
        dup_check.clear()
        for pair in c_list:
            dup_check.add(pair[0])
            dup_check.add(pair[1])

        if len(dup_check) != len(c_list)*2:
            continue

        ret = [''] * n
        chr_i = 97
        for i in range(n):
            if ret[i] is not '':
                continue

            used = False
            for pair in c_list:
                if pair[0] == i:
                    ret[i] = chr(chr_i)
                    ret[pair[1]] = chr(chr_i)
                    used = True
                    chr_i += 1
                    break
            if used:
                c_list.remove(pair)
            else:
                ret[i] = chr(chr_i)
                chr_i += 1

        retstr = ""
        for c in ret:
            retstr += c
        print(retstr)


retstr = ""
chr_i = 97
for i in range(n):
    retstr += chr(chr_i)
    chr_i += 1
print(retstr)