x = list(input())
if len(set(x)) == 1:
    print(-1)
else:
    l = sorted(x)
    for i in range(1,len(l)):
        if l[0] != l[i]:
            l[0],l[i]=l[i],l[0]
            r=''.join(list(reversed(l)))
            if r[0] == '0':
                print(-1)
            else:
                print(r)
            break
    else:
        print(-1)