#include<bits/stdc++.h>
#define int long long
#define double long double
using namespace std;
const int inf=1e18;
void solve(){
    int n;cin>>n;
    vector<int>a(n);
    for(int i=0;i<n;i++)cin>>a[i];
    sort(a.begin(),a.end());
    int ans=inf;
    for(int i=0;i<n-1;i++)ans=min(ans,a[i]*a[i+1]);
    cout<<ans<<"\n";
}
signed main(){
    int t;cin>>t;
    while(t--){
        solve();
    }
}