#include <iostream>
#include <fstream>
#include <map>
#include <string>
#include <sstream>

int main()
{
    std::map<int, int> schools_count;
    int max_count = 0;

    std::ifstream fin("input.txt");
    if (fin.is_open())
    {
        std::string str;

        while (getline(fin, str))
        {

            //считываем в холостую имя и фамилию (Этот кусок я спионерил
            //чтобы вложиться во время)
            const auto name = str.find(' ');
            const auto surname = str.find(' ', name + 1);
            const auto schoolNumberSize = str[surname + 2] == ' ' ? 1 : 2;


            int scool_num = std::stoi(str.substr(surname + 1, schoolNumberSize));

            if (schools_count.find(scool_num) == schools_count.cend())
                schools_count[scool_num] == 0;
            else
            {
                schools_count[scool_num] += 1;
                if (schools_count[scool_num] > max_count)
                    max_count = schools_count[scool_num];
            }
        }

    }
    fin.close();


    std::ofstream fout("output.txt");

    for (std::map<int,int>::const_iterator it = schools_count.cbegin(); it != schools_count.cend(); it++)
    {
        if (it->second == max_count)
            fout << it->first << " ";
    }

    fout.close();

    return 0;
}