// pec.cpp : This file contains the 'main' function. Program execution begins and ends there.
//
#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;
int main()
{
int n;
int k;
cin >> n;
cin >> k;
vector<int>v(n);
for (int i = 0; i < n; i++)
{
cin >> v[i];
}
if (n==1)
{
cout << n << endl;
return 0;
}
if (k == 1)
{
int vys = v[n - 1] - v[0];
vys += 1;
cout << vys << endl;
return 0;
}
priority_queue<int>q;
for (int i = 1; i < n; i++)
{
q.push(v[i] - v[i - 1] - 1);
}
int vys = v[n - 1] + 1 - v[0];
for (int i = 1; i < k; i++)
{
vys -= q.top();
q.pop();
}
cout << vys << endl;
//std::cout << "Hello World!\n";
}
// Run program: Ctrl + F5 or Debug > Start Without Debugging menu
// Debug program: F5 or Debug > Start Debugging menu
// Tips for Getting Started:
// 1. Use the Solution Explorer window to add/manage files
// 2. Use the Team Explorer window to connect to source control
// 3. Use the Output window to see build output and other messages
// 4. Use the Error List window to view errors
// 5. Go to Project > Add New Item to create new code files, or Project > Add Existing Item to add existing code files to the project
// 6. In the future, to open this project again, go to File > Open > Project and select the .sln file
