import string
n = int(input())
cs = string.ascii_lowercase
cm = {cs[i]:i for i in range(len(cs))}
t = 1
def rec(st):
    global t
    if (len(st) >= n):
        print(t, ":", st)
        t += 1
        return 0
    k = max(cm[st[i]]+1 for i in range(len(st)))
    for c in cs[: k + 1]:
        rec(st+c)
    
    
rec('a')