#define _GLIBCXX_DEBUG
#define ll long long
#include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;

int main(){
  int N; cin >> N;
  map<string, int> mpA, mpB;
  for(int i = 0; i < N; i++){
    string S; cin >> S;
    mpA[S] = mpA[S] + 1;
  }
  for(int i = 0; i < N-1; i++){
    string S; cin >> S;
    mpB[S] = mpB[S] + 1;
  }
  for(auto a: mpA){
    if(mpB[a.first] != a.second){
      cout << a.first << endl;
    }
  }
}