ABSP1.cpp

/*My First Template :D*/
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef vector<int> vi;
 
#define INF 1000000000
#define MOD (ll)1000000007
#define pb 	push_back
#define EPS 1e-9
#define FOR(i, n)	for(int i = 0;i < n; i++)
 
template <typename T> T gcd(T a, T b){return (b==0)?a:gcd(b,a%b);}
template <typename T> T lcm(T a, T b){return a*(b/gcd(a,b));}
template <typename T> T mod_exp(T b, T p, T m){T x = 1;while(p){if(p&1)x=(x*b)%m;b=(b*b)%m;p=p>>1;}return x;}
template <typename T> T invFermat(T a, T p){return exp(a, p-2, p);}
template <typename T> T exp(T b, T p){T x = 1;while(p){if(p&1)x=(x*b);b=(b*b);p=p>>1;}return x;}
 
int t;
int n;
int main(){
    cin>>t;
    while(t--){
        cin>>n;
        int arr[n];
        FOR(i, n)   cin>>arr[i];
        ll sum = 0;
        int i = 1;
        for(int j = n-1;j >= 0; j--){
         sum+=(ll)(n-i)*arr[j];   
            i+=2;
        }
        cout<<sum<<endl;
    }
    
	return 0;
}