#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
using uint = unsigned;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
uint n, k;
cin >> n >> k;
vector<uint> a(n);
for (uint i = 0; i < n; i++) {
cin >> a[i];
}
sort(a.begin(), a.end());
uint last = a[0];
vector<uint> t;
t.reserve(n);
uint offset = 0, m = 0;
for (uint i = 0; i < n; i++) {
if (a[i] == last) {
offset++;
} else {
// AAAAA B
// last a[i]
t[i - offset] = a[i] - last - 1;
last = a[i];
m++;
}
}
sort(t.begin(), t.end());
cout << endl;
uint lenght = 0;
for (uint i = 0; i <= m - k; i++) {
lenght += t[i];
}
cout << (lenght + n) << '\n';
}
