View Code of Problem 3929

#include<iostream>
#include<cstring>
#include<string>
#include<algorithm>
#include<vector>
#include<math.h>
#include<map>
#include<typeinfo>
using namespace std;



int main() {
	int n;
	int res = 0;
	int a[999][2];
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> a[i][0];
		a[i][1] = 0;
		for (int j = 0; j < a[i][0]; j++) {
			cin >> res;
			a[i][1] = a[i][1] ^ res;
			
		}
	}
	for (int i = 0; i < n; i++) {
		cout << a[i][1] << "\n";
	}
	return 0;
}