package main

import (
    "fmt"
)

func main() {
    var n int
    fmt.Scan(&n)
    set :=make(map[int]struct{})
    for n%10 != 0 {
        key := n%10
        if _, ok := set[key]; !ok {
            fmt.Print(key)
        }
        set[key] = struct{}{}
        n /= 10
        
    }
}