data = open(0).read().strip()

def is_valid(pw):
    # Passwords must include one increasing straight of at least three letters,
    # like abc, bcd, cde, and so on, up to xyz. They cannot skip letters; abd
    # doesn't count.
    ords = list(map(ord, pw))
    for i in range(len(ords) - 2):
        if ords[i] + 1 == ords[i + 1] and ords[i + 1] + 1 == ords[i + 2]:
            break
    else:
        return False

    # Passwords may not contain the letters i, o, or l, as these letters can be
    # mistaken for other characters and are therefore confusing.
    for c in "iol":
        if c in pw:
            return False

    # Passwords must contain at least two different, non-overlapping pairs of letters, like aa, bb, or zz
    pairs = set()
    for i in range(len(pw) - 1):
        if pw[i] == pw[i + 1]:
            pairs.add(pw[i])
    if not len(pairs) >= 2:
        return False
    return True

def inc(pw):
    pw = list(map(ord, pw))
    for i in range(len(pw) - 1, -1, -1):
        pw[i] += 1
        if pw[i] == ord('z') + 1:
            pw[i] = ord('a')
        else:
            break
    return "".join(map(chr, pw))

part_1 = False
valid_count = 0
while True:
    data = inc(data)
    if is_valid(data):
        valid_count += 1
    if part_1 and valid_count == 1:
        break
    elif valid_count == 2:
        break
print(data)