#include <bits/stdc++.h>
using namespace std;

int main()
{
    int datain, rmdr;
    cin>>datain;
    int tick[10] = {0};
    while(datain != 0)
    {
        rmdr = datain % 10;  //对10取余数 即可实现症数反向
        if(tick[rmdr] == 0)
        {
            tick[rmdr] = 1;
            cout<<rmdr;  
        }
     datain = datain / 10;      
    }
    
return 0;  
}