#include <bits/stdc++.h>
using namespace std;
int main(){
  int T;
  cin >> T;
  for (int i = 0; i < T; i++){
    int N;
    cin >> N;
    int ans = 0;
    vector<int> f(N);
    for (int j = 0; j < N; j++){
      cin >> f[j];
      ans += f[j];
    }
    cout << (ans + 1) % (N + 1) << endl;
  }
}