//
//  main.cpp
//  Parcurgere DFS (infoarena)
//
//  Created by Andrei Bădulescu on 09.12.22.
//

//#include <iostream>
#include <fstream>
#include <bitset>
#include <vector>

using namespace std;

ifstream cin("dfs.in");
ofstream cout("dfs.out");

const int N = 100000;

bitset <N + 1> visited;
vector <int> bridges[N + 1];

int n, m;

void dfs(int current) {
    visited[current] = true;
    
    for (auto next: bridges[current]) {
        if (!visited[next]) {
            dfs(next);
        }
    }
}

int main() {
    cin >> n >> m;
    
    for (auto i = 1; i <= m; i++) {
        int x, y;
        cin >> x >> y;
        bridges[x].push_back(y);
        bridges[y].push_back(x);
    }
    
    int components = 0;
    
    for (auto i = 1; i <= n; i++) {
        if (visited[i]) {
            continue;
        }
        
        components++;
        
        dfs(i);
    }
    
    cout << components;
    return 0;
}