#include<bits/stdc++.h> #define ll long long #define fi first #define se second #define show(x) cout<<#x<<"="<<x<<"\n" using namespace std; int n,m; string s; ll a[50001]; ll b[50001]; int main(){ ios::sync_with_stdio(false); cin.tie(0); cout.precision(10); cout<<fixed; #ifdef LOCAL_DEFINE FILE *stream1; //FILE *stream2; stream1=freopen("in", "r", stdin); //stream2=freopen("out","w",stdout); if(stream1==NULL)return 0; //if(stream2==NULL)return 0; #endif cin>>n>>m; for(int i=0;i<n;i++){ cin>>a[i]; } sort(a,a+n); vector<pair<ll,int> > v; for(int i=1;i<n;i++){ v.push_back(make_pair(a[i]-a[i-1],i)); } sort(v.begin(),v.end()); reverse(v.begin(),v.end()); for(int i=0;i<m-1;i++){ b[i]=v[i].se; } sort(b,b+m-1); ll ans=0; int pre=0; for(int i=0;i<m-1;i++){ ans+=abs(a[pre]-a[b[i]-1]); pre=b[i]; } ans+=abs(a[pre]-a[n-1]); cout<<ans<<"\n"; #ifdef LOCAL_DEFINE cerr << "Time elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " s.\n"; fclose(stream1); //fclose(stream2); #endif return 0; }