#include<iostream>
#include<fstream>
#include<vector>
using namespace std;
ifstream fin ("dfs.in");
ofstream fout ("dfs.out");
vector<int>v[100010];
int n, m, nr=0, viz[100010];
void citire ()
{
    int i, x, y;
    fin>>n>>m;
    for (i=1; i<=m; i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
}
void dfs (int vf)
{
   int i;
   viz[vf]=1;
   for (i=0; i<v[vf].size(); i++)
   {
       if (viz[v[vf][i]]==0)
          dfs(v[vf][i]);
   }
}
int main ()
{
    citire();
    for (int i=1; i<=n; i++)
    {
        if (viz[i]==0)
        {
            dfs(i);
            nr++;
        }
    }
    fout<<nr;
    fin.close();
    fout.close();
}