#include <bits/stdc++.h>
using namespace std;

pair<long long, int> solve(int v[], int sz, int slope) {

	// menghitung DP
	long long dp[sz+1];
	dp[0]=0;
	dp[1]=min(0,v[1]-slope);
	for(int temp=2;temp<sz;temp++)	dp[temp]=min(dp[temp-1],dp[temp-2]+v[temp]-slope);

	// backtracking untuk mencari tahu minimum bilangan yang diambil
	long long opt=dp[sz-1];
	int pos=sz-1,cnt=0;
	while(pos>0)
	{
		if(dp[pos]==dp[pos-1])	pos--;
		else	pos-=2,cnt++;
	}

	return {opt, cnt};
}
int main()
{
	ios_base::sync_with_stdio(false); cin.tie(0);
	int tc;
	cin>>tc;
	while(tc--) {
		int n,k;
		cin>>n>>k;
		int a[n],temp;
		int v[n];
		v[0]=0;
		for(temp=0;temp<n;temp++) {
			cin>>a[temp];
			if(temp>0)	v[temp]=(a[temp]-a[temp-1]);
		}
		int left=0,right=1000000000,mid;
		long long gval,slope;
		int sz=n;
		while(left<=right) {
			mid=(left+right)/2;

			// mencari G optimal dan banyaknya bilangan minimum
			pair<long long, int> ins = solve(v, sz, mid);
			long long opt=ins.first;
			int cnt=ins.second;

			if(cnt<=k) {
				slope=mid;
				gval=opt;
				left=mid+1;
			}

			else	right=mid-1;
		}
		cout<<gval+k*slope<<"\n";
	}
 
}