X = list(input())
X.sort(reverse = True)
if X.count("0") == len(X) - 1 or X.count(X[0]) == len(X):
    print(-1)
    exit()
i = len(X) - 1
while X[i] == X[i - 1]:
    i -= 1
X[i], X[i - 1] = X[i - 1], X[i]
print("".join(X))