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

using namespace std;

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

const int NMAX = 100005;
const int MMAX = 200005;

int n, m, k;
vector <int> muchii[MMAX];
bool vizitat[NMAX];

void dfs(int nod)
{
    vizitat[nod] = true;
    for(unsigned int i = 0; i < muchii[nod].size(); i++){
        if(!vizitat[muchii[nod][i]])
            dfs(muchii[nod][i]);
    }
}

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

    for(int i = 1; i <= n; i++){
        if(!vizitat[i]){
            dfs(i);
            k++;
        }
    }

    fout << k;

    return 0;
}