#include <iostream>
#include <fstream>
#include <vector>
#define NMAX 100100
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int n,viz[100100];
vector <int> graf[NMAX];

void citire()
{
    int m,a,b;
    f>>n; //nr noduri;
    f>>m; //nr muchii;
    for(int i=1; i<=m; i++)
    {
        f>>a>>b;
        graf[a].push_back(b);
        graf[b].push_back(a);//graf neorientat
    }
}
void DFS(int nod)
{
    viz[nod] = 1;
    for(int i=0; i<graf[nod].size(); i++)
    {
        int vecin  = graf[nod][i];
        if(viz[vecin]==0) DFS(vecin);
    }
}
int main()
{
    citire();
    for(int i=1;i<=n;i++)
        viz[i] = 0;
    int an = 0;
    for(int i=1; i<=n; i++)
    {
        if(viz[i]==0)
        {
            an++;
            DFS(i);

        }
    }

    g<<an;
    return 0;
}