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

using namespace std;

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

vector <int> l[100001];
int viz[100001];
int n, m;

void citire()
{
    in>>n>>m;
    int x, y;
    for(int i=1; i<=m; i++)
    {
        in>>x>>y;
        l[x].push_back(y);
        l[y].push_back(x);
    }

}

void dfs(int nod)
{
    viz[nod]=1;
    for(int i=0; i<l[nod].size(); i++)
    {
        if(viz[l[nod][i]]==0)
        {
            dfs(l[nod][i]);
        }
    }
}

int main()
{
    int cc=0;
    citire();

    for(int i=1; i<=n; i++)
    {
        if(viz[i]==0)
        {
            cc++;
            dfs(i);
        }
    }
    out<<cc;

    return 0;
}