#include <fstream>
#include <algorithm>
#include <bitset>
#include <iostream>
#include <vector>

using namespace std;

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

vector <int> L[100001];
bitset <100001> viz;
int n, m;

void DFS(int nod)
{
    viz[nod] = 1;
    for (auto next : L[nod])
        if (!viz[next])
            DFS(next);
}

int main()
{
    fin >> n >> m;
    while (m--)
    {
        int x, y;
        fin >> x >> y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    int nrcc = 0;
    for (int i = 1; i <= n; i++)
        if (!viz[i])
        {
            DFS(i);
            nrcc++;
        }
    fout << nrcc;
    return 0;
}