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//8a032d0f-62fb-44d8-b375-dbc492add052


#include<bits/stdc++.h>

using namespace std;
//#define int long long
typedef long long LL;
#define ii __int128
#define endl '\n'
const int M=20000;
#define mp make_pair
#define pr pair<int,int>
const int mod=1e9+7;
mt19937 rd(time(NULL));

void solve()
{
	int n,m;
	cin>>n>>m;
	vector<int> t(n+1);
	for(int i=1;i<=n;i++) cin>>t[i];
	vector<LL> sum(n+1),pre(n+2);
	for(int i=1;i<=n;i++) sum[i]=sum[i-1]+t[i];
	for(int i=n;i>=1;i--) pre[i]=pre[i+1]+t[i];
	ii ans1=0;
	ii ans2=0;
	for(int i=1;i<=n;i++) ans1+=sum[i],ans2+=pre[i];
	auto cal=[&](int n,int num,vector<int> &xl)
	{
		LL ans=0;
		for(int i=1;i<=n;i++) 
			ans=(ans+(1ll*xl[i]*((((1ll*n*num%mod-i+1+mod)%mod+n-i+1))%mod*num/2)%mod)%mod)%mod;
		return ans;
	};
	if(ans1>ans2)
	{
		LL num=1;
		for(int i=1;i<=m;i++) num=num*2%mod;
		cout<<cal(n,num,t)<<endl;
	}
	else
	{
		vector<int> xl(n*2+1);
		for(int i=1;i<=n;i++) xl[i]=t[n-i+1];
		for(int i=n+1;i<=n*2;i++) xl[i]=t[i-n];
		LL num=1;
		for(int i=1;i<m;i++) num=num*2%mod;
		cout<<cal(n*2,num,xl)<<endl;
	}
}
signed main()
{
	ios::sync_with_stdio(false);
	cin.tie(0),cout.tie(0);
	int T;
	T=1;
	while(T--) solve();
}