#include <iostream>
#include <fstream>
#include <vector>
#define N 100001

using namespace std;

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

vector<int> a[N];
int n, m;
bool viz[N];

void citire()
{
    int x, y;
    fin>>n>>m;
    for(int i=1; i<=m; i++)
    {
        fin>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
}

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

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