#include <iostream>
#include <vector>
#include <fstream>

using namespace std;

void DFS(int s, vector<vector<int>>& adj, vector<bool>& visited) {
    if (visited[s]) return;

    visited[s] = true;
    for (int neighbor : adj[s]) {
        DFS(neighbor, adj, visited);
    }
}

int main() {

    int x, y, n, m, i, conexe;

    ifstream f("dfs.in");
    ofstream g("dfs.out");
    f >> n >> m;

    vector<vector<int>> adj(n + 1);
    vector<bool> visited(n + 1, false);

    for (i = 1; i <= m; ++i) {
        f >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }

    conexe = 0;
    for (i = 1; i <= n; ++i) {
        if (!visited[i]) {
            DFS(i, adj, visited);
            conexe++;
        }
    }

    g << conexe;

    f.close();
    g.close();
    return 0;
}