/*
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,sse4.1,sse4.2,sse4a,popcnt,abm,mmx,avx,avx2")
*/
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/trie_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename T>
using ordered_set = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
#define ll long long
// #define int ll
#define fast cin.tie(0)->sync_with_stdio(0),cout.tie(0)
#define ff first
#define ss second
#define pi pair<int,int>
#define vi vector<int>
#define mi map<int,int>
#define mll map<ll,ll>
#define vll vector<ll>
#define vvi vector<vi>
#define vpi vector<pi>
#define vvll vector<vll>
#define pb push_back
#define p_b pop_back
#define all(x) (x).begin(),(x).end()
#define YES cout<<"YES"
#define NO cout<<"NO"
#define print(a,l,r) for(int qwert=l;qwert<r;qwert++)cout<<a[qwert]<<' '
#define input(a,l,r) for(int qwert=l;qwert<r;qwert++)cin>>a[qwert]
const int M=1e9+7;
const int MOD=998244353;
//const int N=1e6;
const int INF=1e9;
const ll INFLL=2e18;
/*
#define LOCAL
#define TESTCASES
*/
#define int ll
void solve(int test_id){
int n,k;
cin>>n>>k;
int last;
cin>>last;
vector<int>d;
int ans=n;
for(int i=1;i<n;i++){
int x;
cin>>x;
d.pb(x-last-1);
last=x;
}
sort(all(d));
for(int i=0;i<n-k;i++) ans+=d[i];
cout<<ans;
}
signed main(){
fast;
#ifdef LOCAL
auto start = chrono::high_resolution_clock::now();
freopen("input.txt","r",stdin);
freopen("output.txt","w",stdout);
freopen("error.txt","w",stderr);
#endif
int T=1;
#ifdef TESTCASES
cin>>T;
#endif
for(int tests=0;tests<T;tests++){
solve(tests);
//cout<<(solve()?"YES":"NO");
cout<<'\n';
}
#ifdef LOCAL
auto duration = chrono::duration_cast<chrono::microseconds>(chrono::high_resolution_clock::now() - start);
cerr << "time: " << (double)duration.count()/1000.0 << " milliseconds" << endl;
#endif
return 0;
}
