#include <algorithm> #include <bitset> #include <cassert> #include <chrono> #include <cstring> #include <iomanip> #include <iostream> #include <map> #include <queue> #include <random> #include <set> #include <stack> #include <vector> using namespace std; // BEGIN NO SAD #define rep(i, a, b) for(int i = a; i < (b); ++i) #define trav(a, x) for(auto& a : x) #define all(x) x.begin(), x.end() #define sz(x) (int)(x).size() typedef vector<int> vi; // END NO SAD typedef long long ll; typedef pair<int, int> pii; int l[100005]; void solve() { int n, k; cin >> n >> k; for(int i = 0; i < n; i++) cin >> l[i]; int ret = l[n-1] - l[0] + 1; priority_queue<int> q; for(int i = 1; i < n; i++) q.push(l[i] - l[i-1] - 1); while(k-- > 1) { ret -= q.top(); q.pop(); } cout << ret << "\n"; } int main() { ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); solve(); }