#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

ifstream fin("intrare.in");
ofstream fout("iesire.out");

int n, m;
vector<vector <int>> adj;
vector<int> viz;

void DFS(int nod){
    viz[nod] = 1;
    for (int i : adj[nod]){
        if(viz[i]==0) DFS(i);
    }
}

int main()
{
    fin>>n>>m;
    adj.resize(n+5);
    viz.resize(n+5);

    int cnt=0;                          //contor pt comp conexe
    for(int i = 1; i<=m; i++){
        int x,y;
        fin>>x>>y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    for(int i = 1; i <= n; i++){
        if(viz[i] ==0){
            DFS(i);
            cnt++;
        }
    }
    fout<<cnt;
    return 0;
}