#include <bits/stdc++.h>
using namespace std;


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

const int Nmax = 105005;

int n,m;
vector <int> muchii[Nmax];
bool reached[Nmax];


void dfs(int x)
{
    reached[x] = true;
    for (int i = 0; i < muchii[x].size(); ++i)
    {
        int vecin = muchii[x][i];
        if(reached[vecin] == false)
        {
            dfs(vecin);
        }
    }
}



int main()
{
    fin >> n >> m;
    while(m--)
    {
        int x,y;
        fin >> x >> y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }

    int componente = 0;
    for (int i = 1; i <= n; ++i)
    {
        if(!reached[i])
        {
            dfs(i);
            componente++;
        }
    }
    fout << componente;

}