#include <string>
#include <iostream>
#include <vector>
#include<bits/stdc++.h>
using namespace std;
int main()
{
int arr[10] = {0};
int num;
string str;
cin >> num;
str = to_string(num);//int型转string型
int size = str.size();
vector<int> vec;
for(int i = size - 1; i >= 0; i--)
{
int b = str[i] - '0';
if(arr[b] == 0)
{
arr[b]++;
vec.push_back((str[i]-'0'));
}
}
for(int i = 0; i < vec.size(); i++){
cout << vec[i];
}
return 0;
}
#include <iostream>
#include <vector>
#include<bits/stdc++.h>
using namespace std;
int main()
{
int arr[10] = {0};
int num;
string str;
cin >> num;
str = to_string(num);//int型转string型
int size = str.size();
vector<int> vec;
for(int i = size - 1; i >= 0; i--)
{
int b = str[i] - '0';
if(arr[b] == 0)
{
arr[b]++;
vec.push_back((str[i]-'0'));
}
}
for(int i = 0; i < vec.size(); i++){
cout << vec[i];
}
return 0;
}