#include <iostream>
#include <fstream>
using namespace std;
ifstream si("grigo.in");
ofstream so("grigo.out");
const long long MOD=1000003;
bool v[100005];
int main()
{
    long long n,m,a,i,val;
    si>>n>>m;
    for(i=0;i<m;++i)
    {
        si>>a;
        v[a]=1;
    }
    val=1;
    for(i=1;i<=n;++i)
    {
        if(!v[i])
        {
            val=(val*(i-1))%MOD;
        }
    }
    so<<val;
    return 0;
}