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

using namespace std;

void addEdge(vector<vector<int>>& adj, int x, int y) {
    adj[x].push_back(y);
    adj[y].push_back(x);
}

void DFS(vector<vector<int>>& adj, vector<bool>& visited, int node) {
    visited[node] = true;

    for (int neighbor : adj[node]) {
        if (!visited[neighbor]) {
            DFS(adj, visited, neighbor);
        }
    }
}

int countConnectedComponents(vector<vector<int>>& adj, int N) {
    vector<bool> visited(N + 1, false);
    int components = 0;

    for (int i = 1; i <= N; ++i) {
        if (!visited[i]) {
            DFS(adj, visited, i);
            components++;
        }
    }

    return components;
}

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

    int N, M;
    fin >> N >> M;

    vector<vector<int>> adj(N + 1);

    for (int i = 0; i < M; ++i) {
        int x, y;
        fin >> x >> y;
        addEdge(adj, x, y);
    }

    int components = countConnectedComponents(adj, N);

    fout << components << endl;

    fin.close();
    fout.close();

    return 0;
}