#include<iostream>
#include<cstring>
#include<cstdio>


using namespace std;
#define N 1005

int c[N][N];
int a[N];
int n,i,j,T,sum,ans;

int main(){
    memset(c,0,sizeof(c));
    c[0][0]=1;
    for (i=1;i<=1000;i++){
        c[i][0]=1;
        for (j=1;j<=1000;j++){
            c[i][j]=(c[i-1][j-1]+c[i-1][j]) % 2;
        }
    }
    scanf("%d",&T);
    while (T--){
        scanf("%d",&n);
        ans=0;
        for (i=0;i<=n-1;i++){
            ans+=c[n-1][i];
            ans%=2;
        }
        sum=0;
        for (i=1;i<=n;i++){
            scanf("%d",&a[i]);
            sum^=a[i];
        }
        if (ans) printf("%d\n",sum);
        else printf("0\n");
    }
    return 0;
}