#include <bits/stdc++.h>
#include <fstream>

using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");
int n, m;
vector<int> v[100001];
int viz[100001];
int cnt = 0;


void dfs(int nod)
{
    viz[nod] = 1;
    for(auto x : v[nod])
    {
        if(viz[x] == 0)
        {
            dfs(x);
        }
    }
}

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

    for(int i = 1; i<=n; i++)
    {
        if(!viz[i])
        {
            cnt++;
            dfs(i);
        }
    }

    g<<cnt;

    /*for(int i = 1; i<=n; i++)
    {
        cout<<i<<" -> ";
        for(auto x : v[i])
        {
            cout<<x<<" ";
        }
        cout<<endl;
    }*/
    return 0;
}