#include<iostream>
#include<fstream>
#include<vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> a[100001];
bool c[100001],n,m;
void dfs(int nod)
{
    c[nod]=1;
    for (int i=0;i<a[nod].size();i++)
    {
        if (a[nod][i]==0)
            dfs(a[nod][i]);
    }
}
int main ()
{
    fin>>n>>m;
    for (int i=1;i<=m;i++)
    {
        int x,y;
        fin>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    int ct=0;
    for (int i=1;i<=n;i++)
    {
        if (c[i]==0)
        {
            ct++;
            dfs(i);
        }
    }
    fout<<ct;
}