#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

vector <int> v[100001];
int viz[100001],c=0,m,n,a,b;
ifstream reed("dfs.in");
ofstream shaw("dfs.out");

void dfs(int nod)
{
  viz[nod]=1;
  for(auto vec:v[nod]){
    if(viz[vec]==0){
      dfs(vec);
    }
  }
}

int main()
{
  reed>>n>>m;
  for(int i=1;i<=m;i=i+1){
    reed>>a>>b;
    v[a].push_back(b);
    v[b].push_back(a);
  }
    for(int i=1;i<=n;i=i+1){
      if(!viz[i]){
        dfs(i);
        c++;
      }
  }
  shaw<<c;

  return 0;
}