#include<iostream>
using namespace std;
int main(){
int N, num[10]={0};
cin >> N;
while(N != 0){
int n = N % 10;
if(num[n] == 0){
cout << n;
num[n] = 1;
}
N = N / 10;
}
}
#include<iostream>
using namespace std;
int main(){
int N, num[10]={0};
cin >> N;
while(N != 0){
int n = N % 10;
if(num[n] == 0){
cout << n;
num[n] = 1;
}
N = N / 10;
}
}