#include <iostream>

#include<vector>

#include<algorithm>

using namespace std;

#define ll long long

​

void solve()

{

    ll n,x;

    cin>>n>>x;

    vector<ll> v(n);

    for(ll i=0;i<n;i++)

    {

        cin>>v[i];

    }

    sort(v.begin(),v.end());

    v.erase(unique(v.begin(),v.end()),v.end());

    ll s=v.size();

    if(s>n-x)

    {

        s=n-x;

    }

    cout<<s<<"\n";

}

​

int main() {

    int t;

    cin>>t;

    while(t--)

    {

        solve();

    }

    return 0;

}

​