Given an array of citations (each citation is a non-negative integer) of a researcher, write a function to compute the researcher's h-index.

According to the definition of h-index on Wikipedia: "A scientist has index h if h of his/her N papers have at least h citations each, and the other N − h papers have no more than h citations each."

For example, given citations = [3, 0, 6, 1, 5], which means the researcher has 5 papers in total and each of them had received 3, 0, 6, 1, 5 citations respectively. Since the researcher has 3 papers with at least 3 citations each and the remaining two with no more than 3 citations each, his h-index is 3.

Note: If there are several possible values for h, the maximum one is taken as the h-index.

First line is a non-negative integer T(0 < T <= 10) which indicates there are T testcases.
Then there is a non-negative integer n(0 < n <= 10000) which indicates the length of the citations.
After that follows n non-negative integers arr[i] (0 <= arr[i] <= 3 * n)

Output the h-index

/* ***********************************************
Author        :guanjun
Created Time  :2016/3/5 13:17:38
File Name     :neu1683.cpp
************************************************ */
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <stdio.h>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <math.h>
#include <stdlib.h>
#include <iomanip>
#include <list>
#include <deque>
#include <stack>
#define ull unsigned long long
#define ll long long
#define mod 90001
#define INF 0x3f3f3f3f
#define maxn 10010
#define cle(a) memset(a,0,sizeof(a))
const ull inf = 1LL << 61;
const double eps=1e-5;
using namespace std;
priority_queue<int,vector<int>,greater<int> >pq;
struct Node{int x,y;
};
struct cmp{bool operator()(Node a,Node b){if(a.x==b.x) return a.y> b.y;return a.x>b.x;}
};bool cmp(int a,int b){return a>b;
}
int a[maxn];
int main()
{#ifndef ONLINE_JUDGE//freopen("in.txt","r",stdin);#endif//freopen("out.txt","w",stdout);int t,n;cin>>t;while(t--){scanf("%d",&n);for(int i=1;i<=n;i++){scanf("%d",&a[i]);}sort(a+1,a+1+n,cmp);int ans=-INF;for(int i=1;i<=n;i++){if(i>a[i]){ans=i-1;break;}}cout<<ans<<endl;}return 0;
}