x = input()
lst = [i for i in x]
lst.sort(reverse = True)
if lst[0] == lst[-1] or lst[1] == "0":
    print(-1)
    exit()
l = len(lst)
for i in range(l - 1, 0, -1):
    if lst[i] == lst[i - 1]:
        continue
    else:
        lst[i], lst[i - 1] = lst[i - 1], lst[i]
        break
print(int("".join(lst)))