#include <bits/stdc++.h> #define ll long long using namespace std; int main() { ios_base::sync_with_stdio(0); cin.tie(nullptr); int n, k; cin >> n >> k; vector<ll> a(n); for (int i = 0; i < n; i++) { cin >> a[i]; } vector<ll> v; for (int i = 0; i < n - 1; i++) { v.push_back(a[i + 1] - a[i] - 1); } sort(v.begin(), v.end()); ll res = n; for (int i = 0; i < n - k; i++) { res += v[i]; } cout << res; }