#include <fstream>
#include <vector>
#include <algorithm>
#define NMAX 100001
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,nrc;
vector <int> g[NMAX];
void dfs(int x);
void citire();
bool viz[NMAX]; // daca vf a fost viz =1

int main()
{
    int i;
    citire();
    for(i=1;i<=n;i++)
        if(!viz[i])
    {
        nrc++;
        dfs(i);
    }
    fout<<nrc<<'\n';
    return 0;
}

void citire()
{
    int i,j,m;
    fin>>n>>m;
    for(int k=0;k<m;k++)
    {
        fin>>i>>j;
        g[i].push_back(j);
        g[j].push_back(i);
    }
    /*for(i=1;i<=n;i++)
        sort(g[i].begin(),g[i].end());*/

}

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