#include <bits/stdc++.h>
using namespace std;
const int N = 105;
int n, k, a[N];
long long ans;
struct node
{
    int hs, cst, ts;
    bool operator<(const node &_x)
    {
        return cst > _x.cst;
    }
} b[N];
int main()
{
    cin >> n >> k;
    for (int i = 1; i <= n; i++)
    {
        scanf("%d", a + i);
        int v;
        if (a[i] <= k)
            v = a[i];
        else
            v = a[i] / 2;
        b[i].hs = v, b[i].ts = a[i] - v;
        b[i].cst = b[i].hs - b[i].ts;
    }
    sort(b + 1, b + n + 1);
    for (int i = 1; i <= n; i++)
        if (i & 1)
            ans += b[i].hs;
        else
            ans += b[i].ts;
    cout << ans << endl;
    return 0;
}