#include <bits/stdc++.h>
using namespace std;
int n,k,a[1010],max1,t,max2; 
int main()
{
    cin >> n >> k;
    for(int i = 0;i < n;i++) 
	{
		cin >> a[i];
		if(a[i] > max1) max1 = a[i];
	}
    sort(a,a + n);
    for(int i = max1;i >= 1;i--)
    {
    	t = 0; 
		for(int j = 0;j < n;j++)
		{
			if(a[j] >= i - 1 && a[j] <= i) t += a[j];
		}
		if(t > max2) max2 = t;
	}
	cout << max2;
    return 0;
}