#include <iostream>
#include <fstream>
#include <queue>

using namespace std;
vector <int> g[100001];
ofstream out("dfs.out");
int n,m;
bool viz[100001];

void citire()
{
    ifstream f("dfs.in");
    f>>n>>m;
    for(int i=1; i<=m; i++)
    {
        int aux1,aux2;
        f>>aux1>>aux2;
        g[aux1].push_back(aux2);
        g[aux2].push_back(aux1);
    }
}

void dfs(int x)
{
    viz[x]=1;
    for(auto &i: g[x] )
        if(!viz[i])
            dfs(i);
}



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

    return 0;
}