#include <iostream>
#include <fstream>
#include <cstring>
#include <vector>
#include <utility>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <string>
#include <limits>
using namespace std;

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

const int nMax = 100005;
int n, m, cnt;
bool checks[nMax];
vector <int> muchii[nMax];


void dfs(int nod){

    checks[nod] = true;
    for(unsigned int i = 0; i < muchii[nod].size(); ++i)
        if(checks[muchii[nod][i]] == false)
            dfs(muchii[nod][i]);
}

void citire(){
    fin >> n >> m;
    for(int i = 1; i <= m; ++i){
        int a, b;
        fin >> a >> b;
        muchii[a].push_back(b);
        muchii[b].push_back(a);
    }

    for(int i = 1; i <= n; ++i){
        if(checks[i] == false){
            dfs(i);
            ++cnt;
        }
    }
}


int main(){
    citire();
    fout << cnt;
    return 0;
}