#include <bits/stdc++.h>
using namespace std;

int main() {
	int n, m;
	cin >> n >> m;
	int a[n];
	for (int i = 0; i < n; i++) {
		cin >> a[i];
	}
	sort(a, a + n);
	int h = 0;
	int j = 0, k = 0;
	while (j != m) {
		if (a[k] > a[k + 1]) {
			k++;
		}
		a[k]++;
		j++;
	}
	for (int i = 1; i < n - 1; i++) {
		h += a[i];
	}
	cout << h;

	return 0;
}