#include <iostream>
#include <fstream>


using namespace std;


ifstream f("dfs.in");
ofstream g("dfs.out");

/*Sa se determine numarul componentelor conexe ale grafului.*/

int viz[1001],v[1001],cont=0;

void parcurgere(int a[1001][1001],int n,int nod)
{
    int j;
    viz[nod]=1;
    //int ok=0;
    //cout<<nod<<' ';
    for(j=1;j<=n;j++)
        if(a[nod][j]==1 && viz[j]==0)
                parcurgere(a,n,j);




}

int main()
{
    int a[1001][1001],i,n,m;

    f>>n>>m;

    int x,y;

    while(f>>x>>y)
        a[x][y]=a[y][x]=1;

    for(i=1;i<=n;i++)
        if(viz[i]==0)
        {
            cont++;
            //cout<<cont<<' '<<i<<endl;
            parcurgere(a,n,i);

        }

    g<<cont;

    return 0;
}