#include <iostream>
#include <vector>
#include <algorithm>
#include <deque>
using namespace std;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
#define rep(i,n) for(int i=0; i<(n); i++)



int main() {
    int N; cin >> N;
    u64 all_XOR_for_imput = 0;
    rep(i,N-1){
        int u,v; u64 a;
        cin >> u >> v >> a;
        all_XOR_for_imput ^= u;
        all_XOR_for_imput ^= v;
        all_XOR_for_imput ^= a;
    }
    int Q; cin >> Q;
    rep(i,Q){
        int t,x; cin >> t >> x;
        all_XOR_for_imput ^= t;
        all_XOR_for_imput ^= x;
    }
    cout << all_XOR_for_imput << endl;
    return 0;
}

/*
struct ios_do_not_sync{
    ios_do_not_sync(){
        ios::sync_with_stdio(false);
        cin.tie(nullptr);
    }
} ios_do_not_sync_instance;
*/