#include <bits/stdc++.h>
#define Nmax 100005

using namespace std;

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

void Citire()
{
    ifstream f("dfs.in");
    f >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        int x, y;
        f >> x >> y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    f.close();
}

void DFS(int nod)
{
    viz[nod] = 1;
    for(unsigned i = 0; i < L[nod].size(); i++)
    {
        int j = L[nod][i];
        if(viz[j] == 0)
            DFS(j);
    }
}

void Rezolv()
{
    int cnt = 0;
    for(int i = 1; i <= n; i++)
    {
        if(viz[i] == 0)
        {
            cnt++;
            DFS(i);
        }
    }
    ofstream g("dfs.out");
    g << cnt << "\n";
    g.close();
}

int main()
{
    Citire();
    Rezolv();
    return 0;
}