import sys
import itertools

X = list(str(input()))
X = [int(x) for x in X]
X = list(itertools.permutations(X, len(X)))
X = list(set(X))
X = sorted(X, reverse=True)
if len(X) <= 1:
    print(-1)
    exit()
for i in range(len(X[1])):
    if X[1][0] == 0:
        print(-1)
        exit()
    else:
        print(X[1][i],end="")