#include<iostream>
#include<vector>
#include<string>

using namespace std;

bool lex_compare(const int &a, const int &b) {
    int ap = a, bp = b;
    vector<int> da;
    vector<int> db;

    if (ap == 0)
        da.insert(da.begin(), ap%10);
        while (ap > 0) {
            da.insert(da.begin(), ap%10);
            ap /= 10;
        }
        if (bp == 0)
        db.insert(db.begin(), bp%10);
        while (bp > 0) {
            db.insert(db.begin(), bp%10);
            bp /= 10;
        }
        size_t size;
        if (da.size() < db.size()) {
            size = da.size();
        } else {
            size = db.size();
        }

        for (size_t i = 0; i < size; ++i)
            if (da[i] > db[i])
                return true;
            else if (da[i] < db[i])
                return false;
            else
                continue;

        if (da.size() > db.size())
            return false;
        else
            return true;
}

string largestNumber(vector<int>& nums) {
        string res = "";

        sort(nums.begin(), nums.end(), lex_compare);

        for (auto it = nums.begin(); it != nums.end(); ++it)
            res += to_string(*it);

        return res;
    }

int main() {

    vector<int> zeros {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

    cout << largestNumber(zeros) ;
}