#include <bits/stdc++.h> using namespace std; #define ll long long #define pb push_back #define F first #define S second #define pii pair<int,int> #define vi vector<int> #define vpii vector<pii> #define loop(i,n) sloop(0,i,n) #define sloop(s, i, n) for(ll i=(s);i<(n);i++) #define rloop(i,n) rsloop(0,i,n) #define rsloop(s,i,n) for(ll i=(n);i-->(s);) #define all(v) (v).begin(),(v).end() #define nie {cout<<"No\n";return;} #define tak {cout<<"Yes\n";return;} #ifdef DEBUG #define DBG cout << __LINE__ << endl; #else #define DBG #endif //int xses[8] = {-1,1,0,0,-1,1,1,-1}; //int yses[8] = {0,0,-1,1,-1,1,-1,1}; #define int ll void solve() { int n,k; cin>>n>>k; vi v(n); loop(i,n)cin>>v[i]; vi b(n-1); int res=n; loop(i,n-1){ b[i]=v[i+1]-v[i]-1; res+=b[i]; } sort(b.rbegin(),b.rend()); //loop(i,n-1)cout<<b[i]<<' '; //cout<<'\n'; k--; k=min(k,n-1); loop(i,k)res-=b[i]; cout<<res<<'\n'; } signed main() { cin.tie(0); ios_base::sync_with_stdio(0); int t=1; //cin>>t; loop(i,t) { #ifdef DEBUG if(t!=1) { cout<<"Test no. "<<i+1<<endl; } #endif solve(); } cout << '\n'; return 0; }