import sys
readline=sys.stdin.readline
write=sys.stdout.write
from math import gcd as GCD
import math

N=int(readline())
A=list(map(int,readline().split()))
mod=10**9+7
for _ in range(N-1):
    A=[(a+aa)%mod for a,aa in zip(A[:-1],A[1:])]
ans=A[0]
print(ans)