#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h> 
using namespace std;
 
typedef long long ll;
#define S second
#define v vector
#define dbg(x)              cout<<#x<<"="<<(x)<<endl;
#define dbg2(x,y)           cout<<#x<<"="<<(x)<<" "<<#y<<"="<<(y)<<endl;
#define dbg3(x,y,z)         cout<<#x<<"="<<(x)<<" "<<#y<<"="<<(y)<<" "<<#z<<"="<<(z)<<endl;
#define dbg4(x,y,z,w)       cout<<#x<<"="<<(x)<<" "<<#y<<"="<<(y)<<" "<<#z<<"="<<(z)<<" "<<#w<<"="<<(w)<<endl;
#define mp make_pair
#define pb push_back
#define endl                '\n'
#define fast_cin() ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
 

int main()
{
 fast_cin();
 ll t;
 cin >> t;
 while (t--)
 {
     ll x;
     ll i;
     ll n, flag = 0, mx = 0, mn = 1e10 + 1;
     ll k;

     cin >> n >> k;
     set<ll> s1;
     for (i = 0; i < n; i++)
     {
         cin >> x;
         s1.insert(x);

}
ll z =-1;
ll mex = 0;
for (auto it = s1.begin(); it != s1.end();it++)
{
if(*it==z+1)
    z++;
else
{
    mex = z+1;
}

}
mex = z + 1;
if(k==0)
    cout << s1.size() << endl;
else if(mex==*s1.rbegin())
{
    cout << s1.size() << endl;

}
else
{
    if(mex>*s1.rbegin())
        cout << s1.size() + k << endl;
else
{
    ll a = (mex + *s1.rbegin());
if(a%2)
{
    a = a / 2;
    a++;
}
else
{
    a /= 2;
}
s1.insert(a);
cout << s1.size() << endl;

}
}

}
return 0;
}