#include <fstream>
using namespace std;
ifstream in("grigo.in");
ofstream out("grigo.out");
const int MOD=1000003;
bool v[100001];
int main()
{
    long long n,m,i,x,s=1;
    in>>n>>m;
    for(i=1;i<=m;i++)
        {
          in>>x;
          v[x-1]=1;
        }
        for(i=1;i<n;i++)
        {
         if(v[i]==0)
                s=(long long)(s*i)%MOD;
        }
        out<<s;
    return 0;
}