#include <iostream>
#include<fstream>
#include<vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

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

void df(int i)
{
    viz[i]=1;
    for(vector<int>::iterator it=a[i].begin();it!=a[i].end();it++)
    if(viz[*it]==0)
    df(*it);
}

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

void rezolvare()
{
    int k=0;
    for(i=1;i<=n;i++)
    if(viz[i]==0) {k++; df(i);}
    g<<k<<'\n';
}

int main()
{
    citire();
    rezolvare();
    return 0;
}