import itertools

n = int(input())

if n == 1:
    print("n")
    exit()

alp = [chr(i) for i in range(97, 97+26)]
ind = [i for i in range(26)]

ans = []
d = {}
cnt = 0
for i, v in enumerate(itertools.combinations_with_replacement(ind, 5)):
    s0,s1,s2,s3,s4 = v
    now = "a"+alp[s0]+alp[s1]+alp[s2]+alp[s3]+alp[s4]
    if s4 == 13:
        continue
    if now in d:
        continue
    ans.append(now)
    d[now] = 1
    cnt += 1
    if cnt == n-1:
        ans.append(now[::-1]+"n")
        break
    if now[::-1] in d:
        continue
    ans.append(now[::-1])
    cnt += 1
    if cnt == n-1:
        ans.append(now+"n")
        break

print(*ans, sep="\n")