A = list(input())

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