#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N=1e5+5,mod=1e9+7;
int n,m,a[N];
ll lp=0,sum=0;
ll ksm(ll di,ll mi) {ll res=1; for(;mi;mi>>=1,di=di*di%mod) if(mi&1) res=res*di%mod; return res;}
int main() {
    int i,j;
    scanf("%d%d",&n,&m);
    for(i=1;i<=n;i++) scanf("%d",&a[i]);
    long double la=0,lb=0,lc=n;
    for(i=1;i<m;i++) lc/=2;
    for(i=1;i<=n;i++) la+=(2*(n-i+1)-n)*(long double)(a[i]),
        (lp+=1ll*(2*(n-i+1)-n+mod)*a[i])%mod,
        lb+=a[i],(sum+=a[i])%=mod;
    if(la>lb)
        cout<<(n*ksm(2,2*m-1)%mod*sum+ksm(2,m-1)*lp)%mod;
    else
        cout<<(n*(ksm(2,2*m-1))+ksm(2,m-1))%mod*sum%mod;
    return 0;
}