#include<fstream>
using namespace std;
ifstream in("grigo.in");
ofstream out("grigo.out");

const int nmax = 100005, mod =  1000003;
int n, m, x;
bool poz[nmax];
long long rasp = 1;

int main(){
	int player_unu=0;

	in>>n>>m;
	for(int i = 0; i<m; i++)
	{
		in>>x;

		poz[x] = 1;
	}

	for(int i = 1; i<=n; i++)
	{
		if(poz[i]==0)
		{
			rasp *= (i-1);
			rasp %= mod;
		}
	}

	out<<rasp<<'\n';
	return player_unu;
}