#include <bits/stdc++.h>
using namespace std;

class Task {
public:
    void solve() {
        read_input();
        print_output(get_result());
    }

private:
    // numarul maxim de noduri
    static constexpr int NMAX = (int)1e5 + 5; // 10^5 + 5 = 100.005

    // n = numar de noduri, m = numar de muchii/arce
    int n, m;

    // adj[node] = lista de adiacenta a nodului node

    vector<int> adj[NMAX];

    void read_input() {
        ifstream fin("dfs.in");
        fin >> n >> m;
        for (int i = 1, x, y; i <= m; i++) {
            fin >> x >> y; 
            adj[x].push_back(y);
            adj[y].push_back(x);
        }
        fin.close();
    }

    void dfs(int node,vector<int> &visited){
        visited[node]=1;
        for(auto neight : adj[node]){
            if(visited[neight]==0)
                dfs(neight,visited);
        }
    }
    int get_result() {
        int nr=0;
        vector<int>visited(n+1,0);
        for(int i=1;i<=n;i++)
            if(visited[i]==0) {
                dfs(i,visited);
                nr++;
            }
        
        return nr;
    }

    void print_output(int nr) {
        ofstream fout("dfs.out");
        fout<<nr;
        fout.close();
    }
};

// [ATENTIE] NU modifica functia main!
int main() {
    // * se aloca un obiect Task pe heap
    // (se presupune ca e prea mare pentru a fi alocat pe stiva)
    // * se apeleaza metoda solve()
    // (citire, rezolvare, printare)
    // * se distruge obiectul si se elibereaza memoria
    auto* task = new (nothrow) Task(); // hint: cppreference/nothrow
    if (!task) {
        cerr << "new failed: WTF are you doing? Throw your PC!\n";
        return -1;
    }
    task->solve();
    delete task;
    return 0;
}