#include<iostream>
using namespace std;

unsigned int a, b, c[100000], d[1000], w;


int main ()
{

    std::ios::sync_with_stdio(0);


    cin>>a>>b;

    for (int i=0; i<b; i++)
    {
        cin>>c[i];
        for (int k=0; k<a; k++)
        {
            if(c[i]==a-k) d[k]++;
            else cout<<"";

        }

    }

    for (int k=0; k<a; k++)
    {
        if (d[k]%2!=0)
        {
            w++;
        }
        else cout<<"";
    }


    cout<<w;

    return 0;
}