def nth_char(n):
    n %= 25
    if n >= ord('n') - ord('a'): n += 1
    return chr(ord('a') + n)

N = int(input())

for i in range(N):
    first = nth_char(i)
    last = 'n' if i==N-1 else nth_char(i+1)
    w = first
    n = i
    while n > 0:
        r = n % 25
        w += nth_char(r)
        n = n // 25
    w += last
    print(w)