#include<bits/stdc++.h>
using namespace std;
int main(){
long long t;
cin>>t;
while(t--){
long long n,k;
cin>>n>>k;
vector<long long>arr;
for(long long i=1;i<=n;i++){
long long x;
cin>>x;
arr.push_back(x);
}
if(k > n || k == 0){
cout<<-1<<endl;
}else{
cout<<arr[k-1]<<endl;
}
}
return 0;
}