#pragma GCC optimize("O3") #include <bits/stdc++.h> #define ll long long #define str string #define pb push_back #define pf push_front #define in insert #define all(v) v.begin(),v.end() #define fastIO ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); const int sz=1000000,INF=1000000000; using namespace std; void solve() { ll n,m,num,ans; cin>>n>>m; vector<ll>nums,diffs; for(int i=0;i<n;i++) { cin>>num; nums.pb(num); } for(int i=0;i<nums.size()-1;i++) { diffs.pb(abs(nums[i+1]-nums[i])); } sort(all(diffs)),ans=n; for(int i=0;i<diffs.size()-m+1;i++) { ans+=diffs[i]; } cout<<ans; } int main() { fastIO; ll t=1; //cin>>t; while(t--) { solve(); } }