var l = Array(String(readLine()!)).sorted(by: >)
var n = 0
var s = Set(l)
if s.count < 2 || (s.count == 2 && l.contains("0")){
    print(-1)
}else{
    let m = Int(l.map{String($0)}.joined())!
    for i in [Int](1..<l.count).reversed(){
        (l[i-1],l[i]) = (l[i],l[i-1])
        n = Int(l.map{String($0)}.joined())!
        if m != n{
            break
        }
    }
    print(n)
}