#include <iostream>
#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];
bool viz[NMAX];
void citire();
void dfs(int x);

int main()
{
    citire();
    for(int i=1;i<=n;i++){
        if(viz[i]==0){
            nrc++;dfs(i);
        }
    }
    fout<<nrc<<' ';
    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(int i=1;i<=n;i++){
        sort(g[i].begin(),g[i].end());
    }*/
}

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