View Code of Problem 3929

#include <bits/stdc++.h>
using namespace std;
int t,n;
int a[100000];
int main()
{
	cin>>t;
	while(t--) {
		cin>>n;
		int sum=0;
		for(int i=0;i<n;i++) {
			cin>>a[i];
			sum=sum^a[i];
		}
		cout<<sum<<endl;
	}

	
	return 0;
}