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

using namespace std;

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

int viz[100005];
int n, m, nrComConexe;
queue<int> q;
vector<int> graph[100005];

void citire()
{
    int x, y;
    f>>n>>m;
    for(int i=0; i<m; i++)
    {
        f>>x>>y;
        graph[x].push_back(y);
        graph[y].push_back(x);
    }
}

void parcurgereGraf(int nod)
{
    viz[nod]=1;
    for(auto &v : graph[nod])
        if(viz[v]==0)
            parcurgereGraf(v);
}

void dfs()
{
    for(int i=1; i<=n; i++)
        if(viz[i]==0)
        {
            nrComConexe++;
            parcurgereGraf(i);
        }
}

int main()
{
    citire();
    dfs();
    g<<nrComConexe;

    return 0;
}