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

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

int n, m;
vector<vector<int>> adj;
vector<int> viz;

void DFS(int nod) {
    viz[nod] = 1;
    for (int i : adj[nod])
        if (!viz[i])
            DFS(i);
}

int main()
{
    fin >> n >> m;
    adj.resize(n + 5);
    viz.resize(n + 5);
    for (int i = 1; i <= m; i++) {
        int x, y;
        fin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }

    int cnt_comp = 0;
    for (int i = 1; i <= n; i++)
        if (!viz[i]) {
            cnt_comp++;
            DFS(i);
        }

    fout << cnt_comp;

    return 0;
}