#include <bits/stdc++.h>
#include <fstream>

using namespace std;

int viz[100005],n,m;

ifstream f("dfs.in");
ofstream g("dfs.out");
int conexe;
vector < int > v[100005];


void dfs(int nod)
{

    viz[nod]=1;
    vector <int > ::iterator it;
    for(it=v[nod].begin();it!=v[nod].end();++it)
    {
        int nou=*it;
        if(viz[nou]==0)
        dfs(nou);
    }

}

int main()
{
    int a,b;
    f>>n>>m;
    for(int i=1;i<=m;i++)
    {
        f>>a>>b;
        v[a].push_back(b);vector <int > ::iterator it;
        v[b].push_back(a);
    }
   for(int i=1;i<=n;i++)
   if(!viz[i])
   {
       dfs(i);
       conexe++;
   }

    g<<conexe<<'\n';


    return 0;
}