#include <fstream>
#include <vector>
using namespace std;

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

int n, m, viz[100001];
vector <int> L[100001];

void citire()
{
    fin >> n >> m;
    int x, y;
    while(m--)
    {
        fin >> x >> y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
}

void DFS(int nod, int nrcomp)
{
    viz[nod]=nrcomp;
    for(int i=0;i<L[nod].size();i++)
    {
        int v=L[nod][i];
        if(viz[v]==0)
        {
            viz[v]=nrcomp;
            DFS(v, nrcomp);
        }
    }
}

int main()
{
    citire();
    int nrconex=0;
    for(int i=1;i<=n;i++)
    {
        if(viz[i]==0)
        {
            nrconex++;
            DFS(i, nrconex);
        }
    }
    fout << nrconex;
    return 0;
}