import sys
def input():
    return sys.stdin.readline()[:-1]
def main():
    MOD = 10**9 + 7
    N = int(input())
    A = list(map(int,input().split()))
    for k in range(N-1):
        B = [0]*(N-k-1)
        for i in range(N-k-1):
            B[i] = A[i] + A[i+1]
            B[i] %= MOD
        A = B[::]
    print(A[0]%MOD)
if __name__ == '__main__':
    main()