#include<bits/stdc++.h> #define REP(i,n) for(int i=0,i##_len=(n);i<i##_len;++i) #define rep(i,a,b) for(int i=int(a);i<int(b);++i) #define All(x) (x).begin(),(x).end() using namespace std; using ll = long long; int main(){ int N;cin>>N; vector<string> A(N),B; set<string> st; REP(i,N){ string b; cin>>A[i]>>b; if(!st.count(b)){ B.push_back(b); st.insert(b); } } sort(All(A)); REP(i,B.size()){ int k=lower_bound(All(A),B[i])-A.begin(); if(k==N||A[k]!=B[i]){ cout<<B[i]<<endl; } } }