import bisect,collections,itertools,math,functools,heapq
import sys
sys.setrecursionlimit(10**6)
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def I(): return int(sys.stdin.readline().rstrip())

N=I()
A=LI()
ans = 1
mod = 10**9+7
n = 0
sums = 0
for i in range(N):
  ans *= A[i]
  ans %= mod

  if i>=2:
    if n==0:
      n = A[0]
    n *= A[i-1]

ans += n * (N-1)
ans += 3**(N-1) - N
ans %= mod
print(ans)