K=int(input())
c=list(map(int,input().split()))
n=sum(c)
M=10**9+7

fa=[1,1]
fb=[1,1]
for i in range(2,n+1):
  fa+=[fa[-1]*i%M]
  fb+=[fb[-1]*(M//i)*fb[M%i]*fa[M%i-1]*(-1)%M]

from functools import cache
@cache
def f(g):
  a=0
  if all(v%(n//g)==0 for v in c):
    b=fa[g]
    for v in c:
      b*=fb[v//(n//g)]
      b%=M
    a+=b
  return a

from math import gcd
a=0
for i in range(n):
  g=gcd(n,i)
  a+=f(g)

print(a*pow(n,M-2,M)%M)