/////home/mohammed/.config/sublime-text-3/Packages/User
/*input
*/
#include <bits/stdc++.h>
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <numeric>
#include <math.h>
#include <sstream>
#include <iterator>
#include <cstdlib>
#include <unordered_map>
#include <map>
#include <list>
#include <set>
using namespace std;
using bin = std::bitset<8>;
#define endl ("\n")
#define pi (3.141592653589)
#define mod 1000000007
#define int int64_t
#define float double
#define ll long long
#define pb push_back
#define mp make_pair
#define ff first
#define ss second
#define all(c) c.begin(), c.end()
#define min3(a, b, c) min({a,b,c})
#define max3(a, b, c) max({a,b,c})
#define min4(a, b, c, d) min({a,b,c,d})
#define max4(a, b, c, d) max({a,b,c,d})
#define rrep(i, n) for(int i=n-1;i>=0;i--)
#define rep(i,n) for(int i=0;i<n;i++)
#define fast ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr)
#define ld long double
#define scanArray(a,n) for(int i = 0; i < n; i++){cin >> a[i];}
#define coutArray(a,n) for(int i = 0; i < n; i++){cout << a[i] << " ";};cout << endl;
#define input(type, n) type n; cin>>n;
struct debugger
{
template<typename T> debugger& operator , (const T& v)
{
cerr << v << " ";
return *this;
}
} dbg;
bool check_key(map<int, int> m, int key)
{
if (m.find(key) == m.end())
return false;
return true;
}
vector<int> SieveOfEratosthenes(int n)
{
bool prime[n + 1];
memset(prime, true, sizeof(prime));
vector<int> res;
for (int p = 2; p * p <= n; p++)
{
if (prime[p] == true)
{
for (int i = p * p; i <= n; i += p)
prime[i] = false;
}
}
for (int p = 2; p <= n; p++)
if (prime[p])
res.push_back(p);
//cout << p << " ";
return res;
}
// function to convert decimal to binary
bin decToBinary(int n)
{
// array to store binary number
int binaryNum[32];
// counter for binary array
int i = 0;
while (n > 0) {
// storing remainder in binary array
binaryNum[i] = n % 2;
n = n / 2;
i++;
}
string x = "";
// printing binary array in reverse order
for (int j = i - 1; j >= 0; j--) {
x += to_string(binaryNum[j]);
}
bin result{x};
return result;
}
// for example:
// bin result = decToBinary(2);
// bin result2 = decToBinary(10);
// bin z = result xor result2;
// cout << z;
// return 0;
int convertBinaryToDecimal(long long n)
{
int decimalNumber = 0, i = 0, remainder;
while (n != 0)
{
remainder = n % 10;
n /= 10;
decimalNumber += remainder * pow(2, i);
++i;
}
return decimalNumber;
}
int factorial(int n) {
long long res = 1;
for (int i = 1; i <= n; i++) {
res = ((res * i) % mod + mod) % mod ;
}
return res;
}
int32_t main()
{
fast;
input(int, n); input(int, k);
int total_matches = 0;
int total_fuel = 0;
int last;
vector<int> dis;
rep(i, n) {
input(int, x);
if (i == 0) {
total_fuel++;
total_matches++;
last = x;
continue;
}
if (x - 1 == last) {
total_fuel++;
last = x;
} else {
total_fuel++;
dis.pb(x - (last + 1));
total_matches++;
last = x;
}
}
if (total_matches <= k) {
cout << total_fuel << endl;
return 0;
}
sort(dis.begin(), dis.end());
for (int i = 0; i < (total_matches - k); i++) {
total_fuel += dis[i];
}
cout << total_fuel << endl;
}
