#include <bits/stdc++.h>
using namespace std;

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

int n,m;
const int max_muchii = 200000;
int componente = 0;
vector <int> muchii[max_muchii];
bool used[max_muchii];

void dfs(int nod)
{
    used[nod] = true;
    for (int i = 0; i < muchii[nod].size(); ++i)
    {
        int vecin = muchii[nod][i];
        if(used[vecin] == false)
            dfs(vecin);
    }
}

int main()
{
    fin >> n >> m;
    for (int i = 1; i <= m; ++i)
    {
        int x,y;
        fin >> x >> y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }
    for (int i = 1; i <= n; ++i)
    {
        if(used[i] == false)
        {
            componente++;
            dfs(i);
        }
    }
    fout << componente;
}