#include <fstream>

#define MAX 100050
#define R 1000003

using namespace std;

int n, m;
long long sol = 1;
bool important[MAX];

void citire()
{
    ifstream in("grigo.in");
    int a;
    in>>n>>m;
    while(m--)
    {
        in>>a;
        important[a] = true;
    }
    in.close();
}

void solve()
{
    int i;
    sol = 1;
    for(i = 2; i <= n; i++)
    {
        if(!important[i])
            sol = (sol * (i - 1)) % R;
    }
}

void afisare()
{
    ofstream out("grigo.out");
    out<<sol;
    out.close();
}

int main()
{
    citire();
    solve();
    afisare();
    return 0;
}