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

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

vector <int> comp[100001];
vector <int> a[100001];

int n,m,nr,viz[100001];

void ParcurgeAdancime(int i)
{
    int j,v;
    viz[i]=1;
    for(j=0;j<a[i].size();j++)
    {
        v=a[i][j];
        if (viz[v]==0)
        {
            comp[nr].push_back(v);
            ParcurgeAdancime(v);
        }
    }
}

void citire()
{
    int i,x,y;
    f>>n>>m;
    for(i=0;i<m;i++)
    {
        f>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
}

int main()
{
    int i;
    nr=0;
    citire();
    for(i=1;i<=n;i++)
        if(viz[i]==0)
        {
            nr++;
            comp[nr].push_back(i);
            ParcurgeAdancime(i);
        }
    g<<nr;
    return 0;
}