X = list(input())

n = len(X)
X.sort(reverse=True)
for i in range(n - 2, -1, -1):
    if X[i] != X[i + 1]:
        if i > 0 or (i == 0 and X[i + 1] != '0'):
            X[i], X[i + 1] = X[i + 1], X[i]
            print(''.join(X))
            exit()
print(-1)