import sys,heapq
input = sys.stdin.buffer.readline
n=int(input())
A=[int(i) for i in input().split()]
mod=10**9+7
n_max=101
F,FI=[0]*(n_max+1),[0]*(n_max+1)
F[0],FI[0]=1,1
for i in range(n_max):
  F[i+1]=(F[i]*(i+1))%mod
FI[n_max-1]=pow(F[n_max-1],mod-2,mod)
for i in reversed(range(n_max-1)):
  FI[i]=(FI[i+1]*(i+1))%mod
def comb(x,y):
  return (F[x]*FI[x-y]*FI[y])%mod
ans=0
for i in range(n):
  ans=(ans+A[i]*comb(n-1,i))%mod
print(ans)