#include <iostream>
using namespace std;
long long t, n, temp, x, s;
long long arr[1001];
int main() {
cin >> t;
for (int i = 0; i < t; i++) {
cin >> n;
for (int j = 1; j <= n; j++) {
cin >> arr[j];
}
for (int j = 1; j <= n; j++) {
temp = arr[j];
x = j-1;
while (x>0 && arr[x] <= temp) {
arr[x+1] = arr[x];
x--;
}
arr[x+1] = temp;
}
s = 1;
while (arr[s] >= s) {
s++;
}
cout << s-1 << endl;
}
return 0;
}
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