#include <iostream>
#include <fstream>
#include <vector>
#define MAX 100005

using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");
int n, m, viz[MAX], nr;
vector <vector<int> > G(MAX);

void DFS(int start)
{
    int i;
    viz[start] = 1;
    for (auto i : G[start])
    {
        if (!viz[i])
            DFS(i);
    }
}

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

    for (int i = 1; i <= m; i++)
    {
        int x, y;
        f >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for (int i = 1; i <= n; i++)
    {
        if (not viz[i])
        {
            DFS(i); nr++;
        }
    }
    g << nr;

    return 0;
}