def foo(n):
    def bar():
        alph = 'abcdefghijklmopqrstuvwxyz'
        i = 0
        for _1 in alph:
            for _2 in alph:
                for _3 in alph:
                    for _4 in alph:
                        i += 1
                        yield (
                            (f'a{_1+_2+_3+_4}b' if i%2==0 else f'b{_1+_2+_3+_4}a')
                            + ('n' if i==n else ''))
    for i,word in enumerate(bar()):
        if i == n:
            break
        print(word)

if __name__ == '__main__':
    foo(int(input()))