#include <bits/stdc++.h>

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

void dfs(int node, vector <vector <int>>& edges, vector <int>& vis) {
    vis[node] = true;

    for (auto it : edges[node]) {
        if (!vis[it]) {
            dfs(it, edges, vis);
        }
    }
}

int main()
{
    int n, m;
    fin >> n >> m;

    vector <vector <int>> edges(n + 1);
    vector <int> vis(n + 1);
    for (int i = 1; i <= m; i++) {
        int a, b;
        fin >> a >> b;
        edges[a].push_back(b);
        edges[b].push_back(a);
    }

    int ans = 0;
    for (int i = 1; i <= n; i++) {
        if (!vis[i]) {
            ans++;
            dfs(i, edges, vis);
        }
    }

    fout << ans;
    return 0;
}