import sys
n = int(input())
ans = ""
if n == 1:
    print("a")
    sys.exit(0)
else:
    c = 2 ** (n-1)
    for i in range(c):
        tmp = "a"
        for j in range(n-1):
            if i >> j & 1:
                tmp += "b"
            else:
                tmp += "a"
        print(tmp)
