#include <bits/stdc++.h>

using namespace std;

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

const int Nmax = 1e5 + 5;

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

void Dfs(int nod)
{
    viz[nod] = 1;

    for(auto i : L[nod])
        if(!viz[i]) Dfs(i);
}

int main()
{
    fin >> n >> m;

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

    int nrc = 0;
    for(int i = 1; i <= n; i++)
        if(!viz[i])
        {
            nrc++;
            Dfs(i);
        }

    fout << nrc << "\n";

    fin.close();
    fout.close();
    return 0;
}