#include <bits/stdc++.h>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int n,m,insule;
const int N=100005;
bool viz[N];
vector<int >muchii[N];
void dfs(int);
void citire()
{
    f>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        f>>x>>y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
        if(!viz[i])
    {
        insule++;
        dfs(i);
    }
}
void dfs(int nod)
{
  viz[nod]=true;
  for(unsigned int i=0;i<muchii[nod].size();i++)
  {
      int vecin=muchii[nod][i];
      if(!viz[vecin])
        dfs(vecin);
  }
}
int main()
{
    citire();
    g<<insule;
    return 0;
}