#define _GLIBCXX_FILESYSTEM
#include<bits/stdc++.h>
using namespace std;
#define ll long long

void solve() {
    int n;
    cin >> n;
    ll sum = 0;
    for(int i = 0; i < n; i++) {
        ll x;
        cin >> x;
        sum += x;
    }
    ll x, l = 0, r = 1e9, mid;
    while(l <= r) {
        mid = l + (r - l) / 2;
        ll now = mid * mid + mid - 2ll * sum;
        if(now <= 0) {
            x = mid;
            l = mid + 1;
        } else r = mid - 1;
    }
    cout << x + 1 << '\n';
    return;
}

int32_t main() {
    ios_base::sync_with_stdio(false);cin.tie(NULL);
    int tc = 1;
    cin >> tc;
    for(int kase = 1; kase <= tc; kase++) {
        //cout << "Case " << kase << ": ";
        solve();
    }
    return 0;
}