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#include <iostream>
#include <vector>
#include <list>
#include <algorithm>
#include <string>
#include <math.h>
#include <climits>

//#include <chrono>
//#include <fstream>
//#include <bits/stdc++.h>

#define mp make_pair
#define pb push_back
#define eb emplace_back
#define x first
#define y second
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define FOR(i,a,b) for (int i = (a); i < (b); i++)
#define RFOR(i,b,a) for (int i = (b) - 1; i >= (a); i--)

using namespace std;

typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pi;
typedef pair<ll, ll> pl;
typedef vector<int> veci;
typedef vector<bool> vecb;
typedef vector<vector<int>> vvi;
typedef vector<vector<bool>> vvb;

const int INF_I = 1e9;
const ll INF_LL = 1e18;

int main() {
    /*ifstream cin("in.txt");
    ofstream cout("out.txt");
    auto start_time = chrono::high_resolution_clock::now();*/

    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);


    string str;
    vector<string> vec(101);
    int cnt = 0;
    while (cin >> str) {
        /*if (str == "0")
            break;*/
        vec[cnt] = str;
        cnt++;
    }
    sort(vec.begin(), vec.begin() + cnt, [](string a, string b) {
        return a + b > b + a;
    });
    for (int i = 0; i < cnt; i++)
        cout << vec[i];
    cout << endl;

    /*auto end_time = chrono::high_resolution_clock::now();
    chrono::duration<double> duration = end_time - start_time;
    cout << duration.count() << "\n";
    cin.close();
    cout.close();*/
    return 0;
}