#include <iostream>
#include <vector>
#include <fstream>
#include <queue>
#include <algorithm>

using namespace std;

ifstream in("dfs.in");
ofstream of("dfs.out");

const int NMAX = 100000;

vector<int> G[NMAX + 1];
int vis[NMAX+1] = {0};

void DFS(int x){
    vis[x]=1;
    for (auto next: G[x]) {
        if(vis[next] == 0)
            DFS(next);
    }

}

void afisG(int N){
    for (int i = 1; i <= N; ++i) {
        cout<<i<<": ";
        for(auto el : G[i]){
            cout<<el<<", ";
        }
        cout<<endl;
    }
}

int main() {

    int N=0, M;
    in >> N >> M;

    int comp = 0;

    for (int i = 0; i < M; ++i) {
        int x, y;
        in >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    for (int i = 1; i <= N; ++i) {
        if(vis[i] == 0){
            DFS(i);
            comp++;
        }
    }

    of<<comp;

    return 0;
}