x = list(input())
x.sort(reverse=True)

if len(set(x)) == 1 or x[1] == "0":
    print(-1)
else:
    for i in range(len(x)-1, 0, -1):
        if x[i] != x[i-1]:
            x[i], x[i-1] = x[i-1], x[i]
            print("".join(x))
            break