#include <iostream>
#include <vector>
#include <fstream>
using namespace std;

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

int n, m, sol, viz[100010];
vector<int> V[100010];

void dfs(int x)
{
    viz[x] = 1;
    for (vector<int>::iterator it = V[x].begin(); it != V[x].end(); it++)
    {
        if(!viz[*it])
            dfs(*it);
    }
}

int main()
{
    fin >> n >> m;

    //CITIRE
    for (;m;m--)
    {
        int x, y;
        fin >> x >> y;
        V[x].push_back(y);
        V[y].push_back(x);
    }

    //PARCURGERE
    for (int i = 1; i <= n; i++)
    {
        if(!viz[i])
        {
            dfs(i);
            sol++;
        }
    }
    fout << sol;

    return 0;
}