/*

*/
#include <iostream>
#include <fstream>
#include <cmath>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> g[100000];
int n,m,use[100000],nrinsule;
void citire()
{
    int i,x,y;
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
}
void dfs(int nod)
{
    use[nod]=1;
    for(int i=0;i<(int)g[nod].size();i++)
    {
        int vecin=g[nod][i];
        if(!use[vecin])
           {
               dfs(vecin);
           }
    }
}
int main()
{
    citire();
    for(int i=1;i<=n;i++)
    {
        if(!use[i])
        {
            dfs(i);
            nrinsule++;
        }
    }
    fout<<nrinsule;

    return 0;
}