#include <bits/stdc++.h>   using namespace std;   int arr[200007];   int brr[200007];   int main() {     int t;     cin >> t;     while (t--) {       int n, x;       cin >> n >> x;       map<int, int> mpp;       for (int i = 0; i < n; i++) {         cin >> arr[i];         mpp[arr[i]]++;       }       int cnt = 0;       for (int i = 1;; i++) {         if (x == 0) break;         if (mpp[i] == 0) {           mpp[i]++;           x--;         }       }       for (int i = 1;; i++) {         if (mpp[i] == 0)           break;         else           cnt++;       }       cout << cnt << endl;     }     return 0;   }   