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

using namespace std;

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

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

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

int main() {
    int N, M;
    fin >> N >> M;

    vector<vector<int>> adj(N + 1);
    for (int j = 0, x, y; j < M; j++) {
        fin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }

    vector<bool> visited(N + 1, false);
    int count = 0;

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

    fout << count;
    return 0;
}