K=int(input())
c=list(map(int,input().split()))
C=sum(c)
M=10**9+7
fa=[1,1]
for i in range(2,C+1):
  fa+=[fa[-1]*i%M]
g=[0]*(C+1)
for i in range(1,C+1):
  if C%i==0:
    a=1
    for v in c:
      a*=pow(fa[v//i],M-2,M)*(v%i==0)
      a%=M
    g[C//i]=a*fa[C//i]%M
import math
print(sum(g[math.gcd(i,C)] for i in range(1,C+1))*pow(C,M-2,M)%M)