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

using namespace std;

const int N = 100001;

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

vector <int> a[N];

int n;

bool viz[N];

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

void df(int nod)
{
    int y;
    viz[nod] = true;
    for (int i=0; i<a[nod].size(); i++)
    {
        y=a[nod][i];
        if (!viz[y])
            df(y);
    }
}

int main()
{
    int nr = 0;
    citire();
    for(int i=1 ; i<=n ; i++)
        if(!viz[i])
        {
            nr++;
            df(i);
        }
    out << nr << "\n";
    return 0;
}