import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
sys.setrecursionlimit(2*10**5)
yes = lambda :print("yes");Yes = lambda :print("Yes")
no = lambda :print("no");No = lambda :print("No")

#########################################################################
mod = 10**9+7
n = ni()
x = na()
ans = sum(x) * sum(x)
for i in range(n):
    ans -= x[i] ** 2

print((ans * pow(sum(x), mod-2, mod)+1)%mod)