//Normal #define _GLIBCXX_DEBUG #define ll long long #include using namespace std; using Graph = vector>; void print(auto a){ cout << a; } void prints(auto a){ cout << a << " "; } void prints(){ cout << " "; } void printl(auto a){ cout << a << endl; } void printl(){ cout << endl; } void fix(int n){ cout << fixed << setprecision(n); } int siz(string s){ return (int)s.size(); } int main(){ int N; cin >> N; map mp1, mp2; vector X; for(int i = 0; i < N; i++){ string S, T; cin >> S >> T; mp1[S]++; mp2[T]++; if(mp2[T] == 1) X.push_back(T); } for(auto x: X){ if(mp1[x] == 0) printl(x); } return 0; }