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



using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");



int n, m, v[100005];
vector <int>g[100005];



void citire()

{

    int x, y;
   fin>>n>>m;
   for(int i=1; i<=m; ++i){
        fin>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);

   }
}

void dfs(int i)
 {
     v[i]=1;
    for(auto &a:g[i])
        if(!v[a])
            dfs(a);
 }

void DFS()
{
    int nr=0;
	for(int i=1; i<=n; ++i)
	if(!v[i])
	{
	  nr++;
        dfs(i);

	}
	fout<<nr;

}



int main()

{

    citire();
    DFS();

    return 0;

}