n = int(input())
X = [set() for _ in range(26)]
import itertools
for p in itertools.product(range(26), repeat=4):
    s = ''
    for i in range(4):
        s += chr(p[i]+ord('a'))
    if s[-1] == 'n':
        continue
    X[ord(s[0])-ord('a')].add(s)
#print(X[0].pop())

c = 0
for i in range(n):
    if i != n-1:
        s = X[c].pop()
        print(s)
        c = ord(s[-1])-ord('a')
    else:
        print(s[-1]+'n')