#include <bits/stdc++.h>
#include <fstream>
using namespace std;
ifstream fin("dfs.in");
ofstream gin("gfs.out");

int m, n;
vector<vector<int>> adj; // lista de adiacenta
vector<int> viz;

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

int main()
{

    fin >> m >> n;
    adj.resize(n + 5);
    viz.resize(n + 5);

    for (int i = 1; i <= n; 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);
        }
    }
    gin << cnt_comp;
    return 0;
}