#include <iostream>
#include <map>
#include <vector>
#include <string>
#include <set>

using namespace std;

int main()
{
    set<string> names;
    string trash, name;
    set<string> arr;
    int n;
    cin >> n;
    getline(cin, trash);
    for (int i = 0; i < n; i++)
    {
        getline (cin, name);
        if (names.find(name) != names.end())
        {
            arr.insert(name);
        }
        names.insert(name);
    }
    for(auto it = arr.begin(); it != arr.end(); it++)
    {
        cout << *it << endl;
    }
    return 0;
}