#include <bits/stdc++.h>

using namespace std;

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

int n, m;
vector<int> L[100003];
bitset<100003> viz;

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

void DFS(int k)
{
    viz[k] = 1;
    for (int f : L[k])
        if (!viz[f]) DFS(f);
}

void DetNrCompConexe()
{
    int i, nrcc = 0;
    for(i = 1;i <= n;i++)
        if (!viz[i])
        {
            DFS(i);
            nrcc++;
        }
    fout << nrcc << "\n";
}

int main()
{
    Citire();
    DetNrCompConexe();
    fout.close();
}