#include<bits/stdc++.h>   using namespace std;   #define ll long long int    int main()   {       int t;       cin>>t;       while(t--)       {           ll n;           cin>>n;           vector<ll>a(n);           for(ll i=0;i<n;i++)           {               cin>>a[i];           }           ll maxi=INT_MIN;           for(ll i=n-1;i>-1;i--)           {               ll total=0;               total+=a[i];               if(i+a[i]<n)               {                   total+=a[i+a[i]];               }               a[i]=total;               maxi=max<ll>(maxi,total);           }           //cout<<  t ;           cout<<maxi<<  n ;       }   }