sum_max_min

#include <stack>
#include <iostream>
#include <algorithm>
#include <cmath>
#define Mod 1000000007
#define Nmax 1000001
using namespace std;
int n,t;
int V[Nmax],F[Nmax],D[Nmax];
long long sum;

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int x;
    cin>>n>>t;
    D[0]=1;
    for(int i=1;i<Nmax;++i)
        D[i]=(1LL*D[i-1]*2)%Mod;
    for(int i=1;i<=n;++i)
        cin>>x,++F[x];
    int k=0;
    for(int i=0;i<Nmax;++i)
        while(F[i])
            V[++k]=i,--F[i];
    int dr=1;
    for(int i=1;i<=n;++i)
    {
        while(V[i]-V[dr]>t)
            ++dr;
        sum=(sum+1ll*D[i-dr]*V[i])%Mod;
    }
    dr=1;
    for(int i=1;i<=n;++i)
    {
        if(dr<i)
            dr=i;
        while(V[dr+1]-V[i]<=t&&dr<n)
            ++dr;
        sum=sum-(1LL*D[dr-i]*V[i])%Mod;
        while(sum<0)
            sum=Mod+sum;
    }
    cout<<sum;
    return 0;
}