#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
vector<int>v[100000];
int viz[100000],nr,n;
void asd (int x)
{
    viz[x]=1;
    for (int i=0;i<v[x].size();i++)
         if (viz[v[x][i]]==0)
            asd(v[x][i]);

}
int main()
{
   ifstream cin ("dfs.in");
  ofstream cout ("dfs.out");
    int m,i,x,y;
    cin>>n;cin>>m;
   for (i=1;i<=m;i++)
    {
        cin>>x;cin>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for (i=1;i<=n;i++)
    {
        if (viz[i]==0)
            {asd (i);nr++;}
    }
    cout<<nr;

    return 0;
}