//package codeForces;
/*
@author Chandu
Date: 12/03/2024
*/
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.*;
public class Stove {
public static void solveOne(int TestCase, FastScanner in, PrintWriter out) {
int N = in.nextInt();
int K = in.nextInt();
long[] A = new long[N];
for(int i = 0; i < N; i++) {
A[i] = in.nextLong();
}
if(K == 1) {
out.println(A[N - 1] + 1 - A[0]);
} else {
long ans = A[N - 1] + 1 - A[0];
List<Long> diff = new ArrayList<>();
for(int i = 1; i < N; i++) {
diff.add(A[i] - A[i - 1]);
}
Collections.sort(diff);
diff.sort(Collections.reverseOrder());
for(int i = 0; i < K - 1; i++) {
ans -= diff.get(i);
ans++;
}
out.println(ans);
}
}
public static void main(String[] args) {
FastScanner fs = new FastScanner();
PrintWriter out = new PrintWriter(System.out);
int T = 1;
for (int tt = 0; tt < T; tt++) {
solveOne(tt, fs, out);
}
out.close();
}
static final Random random = new Random();
static final int mod = 1_000_000_007;
static void ruffleSort(int[] a) {
int n = a.length;// shuffle, then sort
for (int i = 0; i < n; i++) {
int oi = random.nextInt(n), temp = a[oi];
a[oi] = a[i];
a[i] = temp;
}
Arrays.sort(a);
}
static long add(long a, long b) {
return (a + b) % mod;
}
static long sub(long a, long b) {
return ((a - b) % mod + mod) % mod;
}
static long mul(long a, long b) {
return (a * b) % mod;
}
static long exp(long base, long exp) {
if (exp == 0)
return 1;
long half = exp(base, exp / 2);
if (exp % 2 == 0)
return mul(half, half);
return mul(half, mul(half, base));
}
static long[] factorials = new long[2_000_001];
static long[] invFactorials = new long[2_000_001];
static void precompFacts() {
factorials[0] = invFactorials[0] = 1;
for (int i = 1; i < factorials.length; i++)
factorials[i] = mul(factorials[i - 1], i);
invFactorials[factorials.length - 1] = exp(factorials[factorials.length - 1], mod - 2);
for (int i = invFactorials.length - 2; i >= 0; i--)
invFactorials[i] = mul(invFactorials[i + 1], i + 1);
}
static long nCk(int n, int k) {
return mul(factorials[n], mul(invFactorials[k], invFactorials[n - k]));
}
static void sort(int[] a) {
ArrayList<Integer> l = new ArrayList<>();
for (int i : a)
l.add(i);
Collections.sort(l);
for (int i = 0; i < a.length; i++)
a[i] = l.get(i);
}
static class FastScanner {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
StringTokenizer st = new StringTokenizer("");
String next() {
while (!st.hasMoreTokens())
try {
st = new StringTokenizer(br.readLine());
} catch (IOException e) {
e.printStackTrace();
}
return st.nextToken();
}
int nextInt() {
return Integer.parseInt(next());
}
int[] readArray(int n) {
int[] a = new int[n];
for (int i = 0; i < n; i++)
a[i] = nextInt();
return a;
}
long nextLong() {
return Long.parseLong(next());
}
}
}
Compilation message
stove.java:15: error: class Stove is public, should be declared in a file named Stove.java
public class Stove {
^
1 error
