#include <bits/stdc++.h>
#define NMAX 100000

using namespace std;

vector<int> adj[NMAX];

void dfs(vector<bool> &vis, int _node)
{
    vis[_node] = true;
    
    for (auto node : adj[_node])
    {
        if (!vis[node])
        {
            dfs(vis, node);
        }
    }
}

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

    int n, m;
    f >> n >> m;

    for (int i = 0; i < m; i++) {
        int x, y;
        f >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }

    vector<bool> vis(n + 1, false);
    int cnt = 0;

    for (int i = 1; i <= n; i++)
    {
        if (!vis[i])
        {
            dfs(vis, i);
            cnt++;
        }
    }

    g << cnt;

    return 0;
}