#include <iostream>
#include <fstream>

#define N 100001

using namespace std;

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

struct nod
{
    int info;
    nod* urm;
};

nod* vec[N];
int viz[N];// viz[i]==0

void adaug(int x, int y)
{
    nod* aux = new nod;
    aux->info = y;
    aux->urm = vec[x];
    vec[x] = aux;
}

void  dfs(int x) 
{
    viz[x] = 1;
    nod* p = vec[x];
    while (p != NULL) 
    {
        if (viz[p->info] == 0)
        {
            dfs(p->info);
        }
        p = p->urm;
    }
}

int main()
{
    int n, m;
    fin >> n >> m;
    for (int i = 1; i <= m; i++) 
    {
        int x, y;
        fin >> x >> y;
        adaug(x, y);
        adaug(y, x);
    }
    int cnt = 0;
    for (int i = 1; i <= n; i++)
        if (viz[i] == 0) 
        {
            cnt++;
            dfs(i);
        }
    fout << cnt;
    return 0;
}