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

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
const int nmax = 100005;
vector<int> adj[nmax];
bool viz[nmax];

void dfs(int nod){
    viz[nod] = true;

    for(auto vecin : adj[nod]){
        if(!viz[vecin])
            dfs(vecin);
    }
}


int main(){
    int n, m;
    fin >> n >> m;

    for(int i = 0; i < m; i++){
        int x, y;
        fin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    int conexe = 0;
    for(int i = 1; i <= n; i++){
        if (viz[i] == false){
            conexe ++;
            dfs(i);
        }
    }

    fout << conexe;

    fin.close();
    fout.close();
    return 0;

}