var l = Array(String(readLine()!)).sorted(by: >)
var s = Set(l)
var t = l
t.removeAll(where: {$0 == "0"})
if s.count < 2 || t.count == 1{
    print(-1)
}else{
    let e = l[l.count - 1]
    let f = l.firstIndex(of: e)!
    (l[f - 1],l[f]) = (l[f],l[f - 1])
    print(l.map{String($0)}.joined())
}