#define DEBUG 1

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

vector<int> graf[100001];
bool Vizited[100001];
int NrVf, NrM;

void DFS(int root)
{
    Vizited[root] = true;
    for (int i=0; i<graf[root].size(); i++)
        if (!Vizited[graf[root][i]])
            DFS(graf[root][i]);
}

int main()
{
    ifstream in ("dfs.in");
    ofstream out ("dfs.out");

    int x,y;
    in>>NrVf>>NrM;
    
    for (; NrM>0; NrM--)
    {
        in>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }

    int count = 0;
    for (int i=1; i<=NrVf; i++)
        if (!Vizited[i]) {
            DFS(i); ++count;
        }

    out<<count;

    in.close();
    out.close();
    return 0;
}