#include <fstream>
#define nmax 100005
#define mod 1000003

using namespace std;

ifstream in("grigo.in");
ofstream out("grigo.out");

int n, m;
int v[nmax],poz[nmax];
long long prod=1;

int main()
{
    in>>n>>m;
    for(int i=1; i<=m; i++)
    {
        in>>v[i];
        poz[v[i]]++;
    }
    for(int i=1; i<=n; i++)
    {
        if(poz[i]==0)
        {
            prod *= (i-1)%mod;
            prod %=mod;
        }
    }
    out<<prod%mod;
    return 0;
}