from collections import Counter

x = input()
c = Counter(x)

if len(c.keys()) == 1:
    print(-1)
    exit()

ans = sorted(x, reverse=True)
for i in range(len(ans)-1, -1, -1):
    if ans[i] != ans[i-1]:
        ans[i], ans[i-1] = ans[i-1], ans[i]
        break

if ans[0] == 0:
    print(-1)
    exit()

print(''.join(map(str, ans)))