X = input()
N = [0 for _ in range(10)]

for x in X:
    N[int(x)] += 1

if sum([bool(n) for n in N]) == 1:
    print(-1)
elif sum(N[1:]) == 1:
    print(-1)
else:
    res = []
    for i in range(10)[::-1]:
        res.extend([str(i)] * N[i])
    for i in range(len(res) - 1)[::-1]:
        if res[i] != res[i + 1]:
            res[i], res[i + 1] = res[i + 1], res[i]
            break
    print(''.join(res))