#include <iostream>
#include <fstream>
#include <bitset>
#include <vector>

#define NMAX 100001

using namespace std;

bitset <NMAX> ap;
vector <int> v[NMAX];

inline void dfs(int node){

    ap[node] = 1;

    for (auto it : v[node])
        if (ap[it] == 0)
            dfs(it);

    return;
}

int main()
{

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

    int n, m, x, y;

    f >> n >> m;

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

        v[x].push_back(y);
        v[y].push_back(x);

    }

    int number = 0;
    for (int i = 1; i <= n; i++)
        if (ap[i] == 0){
            number++;
            dfs(i);
        }

    g << number << '\n';

    f.close();
    g.close();

    return 0;
}