n=int(input())
arr=list(map(int,input().split()))

mod=10**9+7

fact=[1]
for i in range(1,n+1):
    fact.append((fact[-1]*i)%mod)
revfact=[]
for i in range(n+1):
    revfact.append(pow(fact[i],mod-2,mod))

def comb(n,k):
    return (fact[n]*revfact[k]*revfact[n-k])%mod

ans=0
for i in range(n):
    ans+=arr[i]*comb(n-1,min(i,(n-1-i)))
    ans%=mod
print(ans)