#include <iostream>
#include <iomanip>
#include <string>
#include <math.h>
#include <algorithm>
#include <cstring>
#include <numeric>
#include <vector>
#include <bitset>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <stack>
#include <unordered_map>
#include <unordered_set>
using namespace std;
#define dbg(x) cerr<<#x<<": "<<x<<"\n";
/*
I love DP
*/
const long long maxN=2e5;
long long arr[maxN+1];
void solve(){
long long n, k; cin>>n>>k;
for(long long i=0 ; i<n ; i++) cin>>arr[i];
long long ans=arr[n-1];
vector<long long>v;
for(long long i=0 ; i<n-1 ; i++){
v.push_back(arr[i+1]-1-arr[i]);
}
sort(v.begin(), v.end(), greater<long long>());
for(long long i=0 ; i<k-1; i++) ans-=v[i];
cout<<ans<<"\n";
}
long long main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
solve();
return 0;
}
Compilation message
cc1plus: error: '::main' must return 'int'
