#include <bits/stdc++.h>
#define Nmax 100001

using namespace std;

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

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

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

int NrCon()
{
    int nr = 0, i;
    for(i = 1; i <= n; i++)
    {
        if(viz[i] == 0)
        {
            nr++;
            DFS(i);
        }
    }
    return nr;
}

int main()
{
    Citire();
    ofstream g("dfs.out");
    g << NrCon() << "\n";
    g.close();
    return 0;
}