#include <bits/stdc++.h>
#define MaxN 100001
using namespace std;

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

#define cin fin
#define cout fout

int n, m, x, y, nr, contor;
int varful[400001], urmatorul[400001], lista[100001];
bitset <MaxN> viz;

void adauga(int x, int y)
{
    nr++;
    varful[nr] = y;
    urmatorul[nr] = lista[x];
    lista[x] = nr;
}

void DFS(int nod)
{
    viz[nod] = 1;
    for(int i = lista[nod]; i != 0; i = urmatorul[i])
    {
        if(!viz[varful[i]])
        {
            DFS(varful[i]);
        }
    }
}


void citire()
{
    cin >> n >> m;
    for(int i=1; i<=m; i++)
    {
        cin >> x >> y;
        adauga(x, y);
        adauga(y, x);
    }
}

void solve()
{
    for(int i=1; i<=n; i++)
    {
        if(!viz[i])
        {
            contor++;
            DFS(i);
        }
    }

    cout << contor;
}

int main()
{
    citire();
    solve();
}