#include <iostream>
#include <fstream>
#include <bits/stdc++.h>
using namespace std;

vector <int> v[100001];
int N,M,i,x,y,viz[100001],rez;
void DFS(int nod)
{
    viz[nod]=1;
    for(int i=0;i<v[nod].size();i++)
    {
        if(viz[v[nod][i]]==0)
        {
            DFS(v[nod][i]);
        }
    }
}
int main()
{

    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    fin>>N>>M;
    for(i=1;i<=M;i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=N;i++)
    {
        if(viz[i]==0)
        {
            DFS(i);
            rez++;
        }
    }
    //cout<<N<<' '<<M;
    fout<<rez;
    fin.close();
    fout.close();
    return 0;
}