MOD = 10 ** 9 + 7
N = 1000
fact = [0 for _ in range(N)]
invfact = [0 for _ in range(N)]
fact[0] = 1
for i in range(1, N):
    fact[i] = fact[i - 1] * i % MOD

invfact[N - 1] = pow(fact[N - 1], MOD - 2, MOD)

for i in range(N - 2, -1, -1):
    invfact[i] = invfact[i + 1] * (i + 1) % MOD

def nCk(n, k):
    if k < 0 or n < k:
        return 0
    else:
        return (fact[n] * invfact[k] % MOD) * invfact[n - k] % MOD

def nHk(n, k):
    return nCk(n + k - 1, k)


n = int(input())
cnt = list(map(int, input().split()))
m = n
times = 1
for c in cnt:
    times *= nCk(m, c)
    m -= c
    times %= MOD
    
tot = 0
for i, c in enumerate(cnt, 1):
    tot += i * (times * pow(nCk(n, c), MOD - 2, MOD) * nCk(n - 1, c - 1))
    tot %= MOD

print(tot * (pow(10, n, MOD) - 1) * pow(9, MOD - 2, MOD) % MOD)