#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N=2e5+20;
const int mod=1e9+7;
int n, m;
int a[N];
int qmi(int a,int b){
    int res=1;
    while(b){
        if(b&1)res=res*a%mod;
        a=a*a%mod;
        b>>=1;
    }
    return res%mod;
}
void solve () {
    cin>>n>>m;
    int sum1=0,sum2=0,pre1=0,pre2=0;
    for(int i=1;i<=n;i++){
        cin>>a[i];
        pre1+=a[i];
        sum1+=pre1;
        sum1%=mod;
    }
    for(int i=n;i>=1;i--){
        pre2+=a[i];
        sum2+=pre2;
        sum2%=mod;
    }
    // cerr<<sum1<<" "<<sum2<<endl;
    int k1=sum1*qmi(2,m-1)%mod;
    int k2=sum2*qmi(2,m-1)%mod;
    int k3=k1*(2ll)%mod;
    int k4=(qmi(2,m-1))*((pre1*(((qmi(2,m)-1)%mod+mod)%mod)%mod))%mod;
    // cerr<<k4<<endl;
    k4=k4*n%mod;
    int ans1=k1+k2+k4;
    // cerr<<k1<<" "<<k2<<" "<<k3<<" "<<k4<<endl;
    int ans2=k4+k3;
    // cerr<<(ans1%mod)<<" "<<(ans2%mod)<<endl;      
    cout<<max(ans1%mod,ans2%mod);

}
signed main () {
    int T = 1; 
    std::ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
    //cin>>T;
    while (T --) solve ();
    return 0;
}