#include<bits/stdc++.h>
using namespace std;
constexpr int M=1e5+5,mod=1e9+7;
int n,m,tmp,sum1,sum2,a[M],pw[M];
int read(){
	int x=0;char ch=getchar();
	while (!isdigit(ch)) ch=getchar();
	while (isdigit(ch)) x=x*10+ch-48,ch=getchar();
	return x;
}
int qpow(int x,int n){
	int s=1; while (n){
		if (n&1) s=1ll*s*x%mod;
		x=1ll*x*x%mod; n>>=1;
	} return s;
}
int rdc(int x){return x>=mod?x-mod:x;}
int getans1(){
	int ans=(1ll*sum2*pw[m]+1ll*(pw[m]-1)*pw[m-1]%mod*n%mod*sum1)%mod;
	return rdc(tmp+mod-ans);
}
int getans2(){
	int rec1=rdc(sum1<<1),rec2=1ll*sum1*(n*2+1)%mod;
	int ans=(1ll*rec2*pw[m-1]+(m>1?1ll*(pw[m-1]-1)*pw[m-2]%mod*(n<<1)%mod*rec1:0))%mod;
	return rdc(tmp+mod-ans);
}
int main(){
	n=read();m=read();
	for (int i=pw[0]=1;i<=m;i++)
		pw[i]=rdc(pw[i-1]<<1);
	for (int i=1;i<=n;i++)
		a[i]=read(),sum1=rdc(sum1+a[i]),
		sum2=(sum2+1ll*i*a[i])%mod;
	tmp=(1ll*n*pw[m]+1)%mod*pw[m]%mod*sum1%mod;
	printf("%d\n",max(getans1(),getans2()));
	return 0;
}