#include <iostream>
#include <fstream>
#include <vector>
#define MAX 100005
using namespace std;

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

int n, m, nr;
vector <vector<int>> G(MAX);
vector <int> viz(100005, 0);

void DFS(int start)
{   int i;
    viz[start] = 1;
    for (auto i : G[start])
    {
        if (viz[i] == 0)
            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 (!viz[i])
            {
                DFS(i);
                ++nr;
            }
    g << nr;
    return 0;
}