#include <iostream>
#include <algorithm>
using namespace std;
int main() {
int cnt;
cin >> cnt;
for(int i = 0; i < cnt; i++) {
int n, m;
cin >> n >> m;
int *a = new int [n];
int ans = 1;
for(int j = 0; j < n; j++) {
cin >> a[j];
}
sort(a, a+n);
int p = 0, q = n - 1;
while(p <= n-1 && q >= 0 && m > 0) {
if((a[p] * a[p+1] > a[q] * a[q-1]) && m >= 2) {
ans = ans * (a[p] * a[p+1]);
p += 2;
m -= 2;
} else {
ans = ans * (a[q]);
q--;
m--;
}
}
cout << ans << endl;
}
return 0;
}