x = int(input())
s = list(str(x))

if len(set(s)) == 1:
    print(-1)
    exit()

s = [int(i) for i in s]
s.sort(reverse=True)

if len(s) == 2:
    ans =  str(s[1])+str(s[0])
    if s[1] == 0:
        print(-1)
        exit()
    else:
        print(ans)
        exit()

ans = str(s[0])+str(s[2])
for i in range(len(s)):
    if i == 0 or i == 2:
        continue
    else:
        ans += str(s[i])
print(ans)