#include <bits/stdc++.h>
using namespace std;
int a[100001];
int main() {
  int T;
  cin >> T;
  while (T--) {
    int n;
    cin >> n;
    memset(a, 0, sizeof a);
    for (int i = 1, x; i <= n; i++) cin >> x, a[x] = 1;
    int m = n, ans = 0;
    while (m) {
      for (int i = 1; i <= 100; i++)
        if (a[i]) a[i] = 0, m--, i++;
      ans++;
    }
    cout << ans << endl;
  }
}
