B_GCD_Partition.cpp

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL);
#define endl '\n'
#define all(x) (x).begin(), (x).end()
#define rep(i, a, b) for (int i = a; i < b; i++)
#define ll long long
ll gcd(ll a , ll b){
    if(b==0) return a;
    return gcd(b , a%b);
}

int main() {
    fastio;

    int t;
    cin >> t;
    while (t--) {
        ll n;
        cin>>n;
        vector<ll> arr(n+1 , 0);
        for(ll i=1;i<=n;i++){
            cin>>arr[i];
            arr[i]+=arr[i-1];
        }
        //cout<<gcd(2 , 4)<<" ";
        int x = 0;
        ll sum = arr[n];
        ll ans = 1;
        //cout<<sum<<" ";
        for(ll i=1;i<n;i++){
            // cout<<arr[i]<<" "<<sum - arr[i]<<endl;
           ans = max(ans , gcd(arr[i] , sum - arr[i]));
        //    cout<<ans<<":"<<endl;
        }
        cout<<ans<<endl;
    }

    return 0;
}