#include<iostream>
using namespace std;

int g[10010];


int main() {
    string s;
    cin >> s;

    for (char c : s) {
        g[c]++;
    }
    int m = 99;
    for (char c : s) {
        m = min(m, g[c]);
    }

    for (char c : s) {
        if (g[c] != m) cout << c;
    }



    return 0;
}