#include <bits/stdc++.h>
     
    #define ll long long int
    #define pb push_back
    #define mp make_pair
    #define vll vector<ll>
    #define f(i, x, y) for (int i = x; i < y; i++)
    #define s(x) sort(x.begin(), x.end())
    #define all(v) v.begin(), v.end()
    #define pll pair<ll, ll>
    #define ff first
    #define ss second
    #define endl "\n"
     
    using namespace std;
    void solve()
    {
     
        int n, k, x;
        cin >> n >> k;
        set<int> s;
     
        for (int i = 0; i < n; i++)
        {
            cin >> x;
            s.insert(x);
        }
     
        if (k == 0)
        {
            cout << n << endl;
            return;
        }
     
        int flag = 0;
        int min = 0;
        for (auto itr = s.begin(); itr != s.end(); itr++)
        {
            if (*itr!=min)
            {
                flag = 1;
                break;
            }
            min++;
        }
     
        if (flag == 0)
        {
            cout << n + k << endl;
            return;
        }
     
        if (s.find(ceil((double)(min + *(--s.end())) / (double)2)) != s.end())
        {
            cout << n << endl;
            return;
        }
        else
        {
            cout << n + 1 << endl;
            return;
        }
     
        return;
    }
     
    int main()
    {
        ios_base::sync_with_stdio(false);
        cin.tie(NULL);
        cout.tie(NULL);
     
        int t;
        cin >> t;
        // t = 1;
        while (t > 0)
        {
            solve();
            t--;
        }
    }