#include<bits/stdc++.h>
#define ll long long
#define yes cout << "YES" << endl
#define no cout << "NO" << endl
#define testing cout << "testing ";
#define mod 1000000007
#define optimize() ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
using namespace std;


void do_the_honour(){

    int n;cin >> n;
    int a[n];
    for(int i=0;i<n;i++) cin >> a[i];

    ll sum=accumulate(a,a+n,0LL);
    ll x=sum;
    ll nn = (-1 + sqrtl(1 + 8 * x)) / 2;


    cout << nn+1 << endl;

}

int main(){
    optimize();
    int t=1;
    cin>>t;
    for(int z=1;z<=t;z++){


    do_the_honour();


}
    return 0;
}