View Code of Problem 3929

#include<stdio.h>
#include<iostream>
#include<cstdlib>
#include<cstdio>
#include<cstring>
#include<string>
#include<algorithm>
#include<vector>
#include<cmath>
#include<stack>
using namespace std;
int p[10000000] = {};
int main() {

	int n;
	cin >> n;
	while (n--) {
		
		int g;
		cin >> g;
		for (int i = 0; i < g; i++) {
			cin >> p[i];
		}

		int sum = 0;
		for (int i = 0; i < g; i++) {
			sum ^= p[i];
		}
		cout << sum << endl;
	}
	return 0;
}