#include <fstream>
#include <iostream>
#include <vector>
#define nmax 100005

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

int n, m, viz[nmax], k;
vector <int> G[nmax];

void read(){
    int x, y;
    fin >> n >> m;
    for(int i = 1; i <= m; ++i){
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

void DFS(int nod){
    viz[nod] = 1;
    for(int i = 0; i < G[nod].size(); ++i)
        if(!viz[G[nod][i]])
            DFS(G[nod][i]);
}

int main(){

    read();
    for(int i = 1; i <= n; ++i)
        if(!viz[i]){
            DFS(i);
            k++;
        }
    fout << k;
    fin.close();
    fout.close();
    return 0;
}