#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
vector <int> graph[100010];

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

int viz[100010];
int n, m;

void citire() {
    f >> n >> m;
    for (int i = 0; i < m; i++){
        int a, b;
        f >> a >> b;
        graph[a].push_back(b);
        graph[b].push_back(a);
    }
}

void DFS(int node){
    viz[node] = 1;

    int lim = graph[node].size();
    for(int i = 0; i < lim; i ++){
        int vecin = graph[node][i];
        if(!viz[vecin])
            DFS(vecin);
    }
}

int main() {
    int conexe = 0;
    citire();
    for(int i = 1; i <= n; i ++){
        if(!viz[i]) {
            conexe++;
            DFS(i);
        }
    }
    g << conexe;
    return 0;
}