import sys

def all_same(s):
    return all(c == s[0] for c in s)

def previous_permutation(arr):
    n = len(arr)
    i = n - 2
    while i >= 0 and arr[i] <= arr[i + 1]:
        i -= 1
    if i == -1:
        return False
    j = n - 1
    while arr[j] >= arr[i]:
        j -= 1
    arr[i], arr[j] = arr[j], arr[i]
    arr[i + 1:] = reversed(arr[i + 1:])
    return True

def solve():
    X = sys.stdin.readline().strip()
    digits = list(X)
    if all_same(digits):
        print(-1)
        return
    max_digits = sorted(digits, key=lambda x: -int(x))
    if not previous_permutation(max_digits):
        print(-1)
        return
    if max_digits[0] == '0':
        print(-1)
    else:
        print(''.join(max_digits))

solve()