#include <iostream>
#include <vector>
using namespace std;

int main() {
    int a;
    cin >> a;
    vector<int> count(10);
    while(a){
        int remainder = a % 10;
        if(count[remainder] == 0){
            count[remainder]++;
            cout<<remainder;
        }
        a /= 10;
    }
    cout<<endl;
}
// 64 位输出请用 printf("%lld")

别整复杂了