N = int(input())
MOD = 10 ** 9 + 7
A = list(map(int, input().split()))
for i in range(N - 1):
    for j in range(len(A) - 1):
        A[j] = (A[j] + A[j + 1]) % MOD
    A = A[:len(A) - 1]
print(A[0])