#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

int viz[100002];
vector<int>graph[100002];

void parcurgere_adancime(int nod)
{

    viz[nod]=1;
    int lim=graph[nod].size();
    for(int i=0; i<lim; i++)
        if(viz[graph[nod][i]]==0)
                parcurgere_adancime(graph[nod][i]);
}

int main()
{
    int n,m;
    ifstream f("dfs.in");
    ofstream g("dfs.out");
    f>>n>>m;
    int k=0;
    for(int i=1; i<=m; i++)
    {
        int a,b;
        f>>a>>b;
        graph[a].push_back(b);
        graph[b].push_back(a);
    }
    for(int i=1; i<=n; i++)
        if(viz[i]==0)
        {
            parcurgere_adancime(i);
            k++;
        }
    g<<k;
    return 0;
}