View Code of Problem 3929

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cmath>
#include<cstring>
#include<vector>
#include<map>
#include<string>
#include<set>
using namespace std;
int main(){
    int t;
    cin>>t;
    while(t--)
    {
        int n;
        cin>>n;
        int ans=0;
        for(int i=0;i<n;i++)
        {
            int a;
            cin>>a;
            ans=ans^a;
        }
        cout<<ans<<endl;
    }
    return 0;
}
/*


*/