// Example program
#include <iostream>
#include <string>
#include <set>
#include <algorithm>

int main()
{
    int n;
    std::cin >> n;
    std::set<std::string> all, cheaters, non_cheaters;
    for (int i=0;i<n;++i) {
        std::string a,b;
        std::cin >> a >> b;
        all.insert(b);
        cheaters.insert(a);
    }
    std::set_difference(all.begin(), all.end(), cheaters.begin(), cheaters.end(), std::inserter(non_cheaters, non_cheaters.end()));
    for (const auto& s : non_cheaters)
        std::cout << s << std::endl;
    return 0;
}