#include <iostream>
#include <fstream>
#include <vector>
#define NLIM 100001

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int n, m;

vector<int> Muchii[NLIM];
int viz[NLIM];

void DFS(int nod) {
    viz[nod] = 1;
    for(int i=0; i<Muchii[nod].size(); i++) {
        int vecin = Muchii[nod][i];
        if(viz[vecin] == 0)
            DFS(vecin);
    }
}

void citire() {
    f >> n >> m;
    for(int i=1; i<=n; i++) viz[i]=0;
    for(int i=1; i<=m; i++) {
        int s, d;
        f >> s >> d;
        Muchii[s].push_back(d);
        Muchii[d].push_back(s);
    }
}
void afisare() {
    int s = 0;
    for(int i=1; i<=n; i++)
        if(viz[i] == 0) {
            DFS(i);
            s++;
        }
    g << s << '\n';
}

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