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

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

const int nmax = 100005;

class conexe{

    vector < int > list[nmax];
    bool vis[nmax];
    int n, m;

public:

    void read();
    void dfs(int node);
    void count();

};

void conexe :: read()
{
    in >> n >> m;

    for(int i = 1; i <= m; ++i)
    {
        int x, y;

        in >> x >> y;

        list[x].push_back(y);
        list[y].push_back(x);
    }
}

void conexe :: dfs(int node)
{
    vis[node] = 1;

    int val = list[node].size();

    for(int i = 0; i < val; ++i)
    {
        int new_node = list[node][i];

        if(vis[new_node] == 0)
            dfs(new_node);
    }
}

void conexe :: count()
{
    int number = 0;

    for(int i = 1; i <= n; ++i)
        if(vis[i] == 0)
        {
            dfs(i);
            number++;
        }

    out << number;
}

int main()
{
    conexe C;

    C.read();
    C.count();

    return 0;
}