#include <iostream>
#include<bits/stdc++.h>
#define ll long long
using namespace std;
ll t[100001];
int main() {
    std::ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);
    ll k, n, sum = 0;
	cin >> n >> k;
	for (int i = 1; i <= n; i++)
		cin >> t[i];
	sort(t, t + n);
	for (int i = 1; i <= n; i++)
	{
		if (i <= k)
			sum +=t[i];
	}
	cout << sum - 1 <<"\n";
    return 0;
}