#include <fstream>
#include <vector>

using namespace std;

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

int n,m,k;
vector <int> a[200009];
bool viz[100009];

void citire ()
{
    int x,y;
    for (int i=0 ; i<m ; i++)
    {
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
}

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

int main()
{
    in>>n>>m;
    citire ();
    for (int i=1; i<=n ; i++)
    {
        if(!viz[i])
        {
            k++;
            dfs(i);
        }
    }
    out<<k;
}