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

#define NLIM 100005

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

int vizitat[NLIM];
vector<int> muchii[NLIM];

void dfs(int nod)
{
    vizitat[nod] = 1;

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

int main()
{
    int n, m, a, b;
    f>>n>>m;
    for(int i = 0; i < m; i++)
    {
        f>>a>>b;
        muchii[a].push_back(b);
        muchii[b].push_back(a);
    }

    unsigned int k = 0;
    for(int i = 1; i <= n; i++)
    {
        if(!vizitat[i])
        {
            k++;
            dfs(i);
        }
    }

    g<<k;
}