#include <fstream>
#include <vector>
#define NMAX 100002

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

int n, nr;
vector<int> g[NMAX]; ///g[1] -> lista de adiac a vf i
bool viz[NMAX];

void citire();
void dfs(int x);
int main()
{
    int i;
    citire();
    for (i=1; i<=n; i++)
        if (!viz[i])
           {
            nr++;
            dfs(i);
           }
    fout<<nr<<'\n';
    fin.close();
    fout.close();
    return 0;
}

void citire()
{
 int i, j, k, m;
 fin>>n>>m;
 for (k=1; k<=m; k++)
     {
      fin>>i>>j;
      g[i].push_back(j);
      g[j].push_back(i);
     }
}

void dfs(int x)
{
 int i;
 viz[x]=1;
 for (i=0; i<g[x].size(); i++)
     if (!viz[g[x][i]])
        dfs(g[x][i]);
}