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

using namespace std;

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

bool vizitat[1000];

struct node
{
    int x;
    node *v;
};

node *noduri[100005];

void add(node *&dest, int val)
{
    node *p;
    p = new node;
    p->x = val;
    p->v = dest;
    dest = p;
}

void dfs(int nod)
{
    vizitat[nod] = true;
    node *i;
    for (node *i = noduri[nod]; i != NULL; i = i->v)
    {
        if (vizitat[i->x] == false)
            dfs(i->x);
    }
}

int main()
{

    int n, m;
    in >> n >> m;
    for (int i = 0; i < m; i++)
    {
        int x, y;
        in >> x >> y;
        add(noduri[x], y);
        add(noduri[y], x);
    }
    int nr = 0;
    for (int i = 1; i <= n; i++)
    {
        if (vizitat[i] == false)
        {
            dfs(i);
            nr++;
        }
    }
    out << nr;
    return 0;
}