N=int(input())
a=list(map(int,input().split()))
ans=a[0]+a[N-1]
b=[1 for i in range(N+1)]
for i in range(1,N+1):
    b[i]=b[i-1]*(N-i)//i
for i in range(1,N-1):
    ans+=a[i]*b[i]
print(ans % 1000000007)