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

std::ifstream fin("dfs.in");
std::ofstream fout("dfs.out");

std::vector<int> noduri[100002];
int n, m;
int visited[100002];

void citire()
{
    fin>>n>>m;
    int a, b;

    for(int i = 0; i < m; i++)
    {
        fin>>a>>b;
        noduri[a].push_back(b);
        noduri[b].push_back(a);
    }
}


void dfs(int nod)
{
//    std::cout<<nod<<' ';
    visited[nod] = 1;

    for(int i = 0; i < noduri[nod].size(); i++)
    {
        if(!visited[noduri[nod][i]])
        {
            dfs(noduri[nod][i]);
        }
    }
}

void rezolvare()
{
    int nr = 0;
    for(int i = 1; i <= n; i++)
    {
        if(!visited[i])
        {
            dfs(i);
            nr++;
        }
    }
    fout<<nr<<'\n';
}

int main()
{
    citire();
    rezolvare();
    return 0;
}