#include <bits/stdc++.h>
using namespace std;
vector <int> muchii[100100];
int n, m;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int vizitat[100100];
int ans = 0;
void dfs(int NOD)
{
    vizitat[NOD] = 1;
    for(unsigned int i = 0; i < muchii[NOD].size(); i ++)
    {
        if(vizitat[muchii[NOD][i]] == 0)
        {
            dfs(muchii[NOD][i]);
        }
    }
}
void citire()
{
    fin >> n >> m;
    for(int i = 1; i <= m; i ++)
    {
        int x, y;
        fin >> x >> y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }
    for(int i = 1; i <= n; i ++)
    {
        if(vizitat[i] == 0)
        {
            ans++;
            dfs(i);
        }
    }
}
int main()
{
    citire();
    fout << ans << '\n';
}