#include<iostream>
#include<algorithm>
#include<vector>

using namespace std;
vector<long long>q;
int main() {
	long long  n,k;
	cin >> n>>k;
	for (int i = 0;i<n-1; i++) {
		long long  x;
		cin >>x ;
		q.push_back(x);
	}
	sort(q.begin(), q.end());
	q.erase(q.end() - k, q.end());
	long long  ans = 0;
	for (int i = 0; i < q.size(); i++) {
		ans += q[i];
	}
	cout << ans;
	return 0;
}