#include <bits/stdc++.h>
#include <iostream>
#include <fstream>
#include <vector>
#define NMAX 100005

using namespace std;

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

int N, M, cnt;
bool viz[NMAX];
vector <int> v[NMAX];

void dfs(int nod)
{
    viz[nod] = 1;
    for (vector <int> :: iterator it = v[nod].begin(); it != v[nod].end(); it++)
    {
        int nxt = *it;
        if (!viz[nxt])
            dfs(nxt);
    }

}

int main()
{
    fin >> N >> M;

    for (int i = 1; i <= M; i++)
    {
        int x, y;
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for (int i = 1; i <= N; i++)
    {
        if (!viz[i])
        {
            cnt++;
            dfs(i);
        }
    }
    fout << cnt << "\n";
    return 0;
}