// LUOGU_RID: 98398783
// LUOGU_RID: 98398708
#include<bits/stdc++.h>
using namespace std;
const int MAXN=1e5+1;
int a[MAXN],n,k;
map <int,int> cnt;
inline bool check(int mex) {
	vector <bool> vis(mex,false);
	int tot=0,lim=0;
	for(int i=1;i<=n;++i) {
		if(a[i]<mex) vis[a[i]]=true;
		else ++lim;
	}
	for(int i=0;i<mex;++i) {
		if(!vis[i]) {
			++tot;
			if(tot>k||tot>lim) return false;
		}
	}
	return true;
}
inline int count(int mex) {
	vector <bool> vis(mex,false);
	int tot=0;
	for(int i=1;i<=n;++i) if(a[i]<mex) vis[a[i]]=true;
	for(int i=0;i<mex;++i) if(!vis[i]) ++tot;
	return tot;
}
inline void solve() {
	int mex=0,diff=0;
	scanf("%d%d",&n,&k);
	cnt.clear();
	for(int i=1;i<=n;++i) {
		scanf("%d",&a[i]);
		++cnt[a[i]];
	}
	int l=0,r=n;
	while(l<=r) {
		int mid=(l+r)>>1;
		if(check(mid)) mex=mid,l=mid+1;
		else r=mid-1;
	}
	priority_queue <int,vector<int>,greater<int> > q;
	for(auto p:cnt) {
		++diff;
		if(p.first>mex)	q.push(p.second);
	}
	int lim=count(mex);
	for(int i=1;!q.empty()&&i<=lim;++i) {
		int x=q.top(); q.pop();
		if(x>1) ++diff,q.push(x-1);
	}
	if(q.empty()) puts("0");
	else printf("%d\n",diff-mex);
}
signed main() {
	int T;
	scanf("%d",&T);
	while(T--) solve();
	return 0;
}