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

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

struct nod{
    bool visited;
    vector <int> vecini;
};

int n, m, result;
nod nods[100100];

void DFS(int i)
{
    if(nods[i].visited == 0)
    {
        nods[i].visited = 1;
        for(int j = 0; j < nods[i].vecini.size(); j++)
            DFS(nods[i].vecini[j]);
    }
}

int main()
{
    fin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        int x, y;
        fin >> x >> y;
        nods[x].vecini.push_back(y);
        nods[y].vecini.push_back(x);
    }

    for(int i = 1; i <= n; i++)
    {
        if(nods[i].visited == 0){
            result++;
            DFS(i);
        }
    }
    fout << result;

    return 0;
}