#include <iostream>
#include <vector>
#include <fstream>
using namespace std;

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

int n, m;
vector <int> * lv;

int * visited;

void DFS(int node){

    visited[node] = 1;

    for(int i = 0; i < lv[node].size(); i++){

        if(!visited[lv[node][i]])

            DFS(lv[node][i]);
    }
}

int main(){

    f >> n >> m;

    lv = new vector <int>[n + 1];
    visited = new int[n + 1];

    for(int i = 0 ;i <= n; i++)
        visited[i] = 0;

    int x, y;
    for(int i = 0; i < m; i++){

        f >> x >> y;
        lv[x].push_back(y);
        lv[y].push_back(x);
    }

    int n_comp_conected = 0;

    for(int i = 1; i <= n ; i++){

        if(!visited[i]){

            DFS(i);
            n_comp_conected += 1;
        }
    }

    g << n_comp_conected;

    return 0;
}