#include<bits/stdc++.h>
#define fst ios_base::sync_with_stdio(false), cin.tie(NULL),cout.tie(NULL);
#define ll long long 
#define endl '\n'
using namespace std;
int main(){
    fst
    int t;
    cin >> t;
    while(t--){
        int n;
        cin >> n;
        vector<int> a(n);
        for(int i=0;i<n;i++) cin >> a[i];
        sort(a.begin(),a.end());
        auto ok = [&](int mid){
            map<int,int> mp;
            int cnt = 0, m = 0, tmp = n, k = 0;
            for(int i=0;i<n;i++) mp[a[i]]++;
            for(int i=1;i<=mid;i++){
                int res = mid - i + 1;
                if(cnt > 0 && mp[res] > 0){
                    cnt=0;
                    mp[a[k]]--;
                    if(mp[a[k]] == 0) k++;
                }
                if(mp[res] > 0 && cnt == 0){
                    m++;
                    mp[res]--;
                    tmp--;
                    if(tmp == 0) break;
                    else cnt++;
                }
                else {
                    int r = 0;
                    for(int j=n-1;j>=0;j--){
                        if(a[j] <= res && cnt > 0 && mp[a[j]] > 0){
                            cnt = 0;
                            mp[a[k]]--;
                            if(mp[a[k]] == 0) k++;
                        }
                        else if(cnt == 0 && a[j] <= res && mp[a[j]] > 0){
                            r = a[j];
                            break;
                        }
                    }
                    if(r && mp[r] > 0){
                        m++;
                        mp[r]--;
                        tmp--;
                        if(tmp == 0) break;
                        else cnt++;
                    }
                    else break;
                }
            }
            return m == mid;
        };
        int l=1,r=100,mid,ans=0;
        while(l <= r){
            mid = (l + r) / 2;
            if(ok(mid)){
                ans = mid;
                l = mid + 1;
            }
            else r = mid - 1;
        }
        cout << ans << endl;
    }
    return 0;
}