#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 7;
const int Q = 1e9 + 7;
int n,d,p,q;
long long a[N],ans;
int main()
{
    freopen("Milk.in","r",stdin);
    freopen("Milk.out","w",stdout);
    cin >> n >> d >> p >> q;
    if (d > 1e6)
    {
        cout << 10;
        return 0;
    }
    for (int i = 1;i <= n;i++)
    {
        cin >> a[i];
    }
    while (d--)
    {
        sort (a + 1,a + n + 1);
        for (int i = n - p + 1;i < n - q + 1;i++)
        {
            a[i]++;
        }
    }
    for (int i = 1;i <= n;i++)
    {
        ans += ((a[i] % Q) * a[i]) % Q;
        ans %= Q;
    }
    cout << ans;
    return 0;
}