#include<stdio.h>
long long int a[10001][101];
int main()
{
	int n, m, sum = 1, i, j;
	scanf("%d %d", &n, &m);
	a[0][1] = 1;
	for (i = 1; i < 10001; i++)
		for (j = 1; j <= 101; j++)
			a[i][j] = (a[i - 1][j - 1] + a[i - 1][j]);
	for (i = 0; i < m; i++)
	{
		scanf("%d", &j);
		sum = (sum * a[n][j+1]) % 10007;
		n -= j;
	}
	printf("%lld", sum);
	return 0;
}