#include<fstream>
#include<vector>
using namespace std;
ifstream cin("dfs.in");
ofstream cout("dfs.out");

int n,m;
int x,y;
int viz[100005];

vector<int> G[100005];

void DFS(int nod){

  viz[nod]=1;

  for(int i=0;i<G[nod].size();i++)
    if(!viz[G[nod][i]]) DFS(G[nod][i]);

}

int main(){

  cin>>n>>m;
  for(int i=1;i<=m;i++){

    cin>>x>>y;
    G[x].push_back(y);
    G[y].push_back(x);

  }

  int cnt=0;

  for(int i=1;i<=n;i++)
    if(!viz[i]) DFS(i),++cnt;

  cout<<cnt;

}