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

using namespace std;

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

int n, m, viz[100005];
vector <int> G[100005];

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

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

int nr_comp()
{
    int nr = 0;
    for(int i = 1; i <= n; i++)
        if(!viz[i])
        {
            dfs(i);
            nr++;
        }
    return nr;
}

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