#yukicoder
import copy
X = list(input())
X = sorted(X)[::-1]
XX = copy.deepcopy(X)

for i in range(len(X)-1,0,-1):
    if XX[i] != XX[i-1]:
        XX[i],XX[i-1] = XX[i-1],XX[i]
        break
if XX[0] == "0" or X == XX:
    print(-1)
else:
    print(*XX,sep="")