#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

const int N = 1e5;
vector <int> a[N+1];
int viz[N+1];

void dfs (int x)
{
    viz[x]=1;
    for(auto y:a[x])
    {
        if(!viz[y])
        {
            dfs(y);
        }
    }
}
int main ()
{
    ifstream in("dfs.in");
    ofstream out("dfs.out");
    int n , m , nc=0;
        in >> n >> m;
    for (int i = 0; i < m; i++)
    {
        int x, y;
        in >> x >> y;
        a[x].push_back(y);///il adauga pe y la sfarsitul listei de adiacenta a lui x (a[x])
        a[y].push_back(x);///il adauga pe y in lista lui x
    }
    in.close();

    for (int i = 1; i <= n; i++)
    {
        if(!viz[i])
        {
            nc++;
            dfs(i);
        }
    }

    out<<nc;

    out.close();
    return 0;
}