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

int main() {
    map<int, int> cnt;
    string s;
    cin >> s;
    for(auto x : s){
        cnt[x] += 1;
    }
    int mn = cnt.size();
    for(auto m : cnt)  mn = min(mn, m.second);
    for(auto p : s){
        if(cnt[p] == mn) continue;
        cout << p;
    }

}