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

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


vector <int> g[100005];
bool visited[100005];


void DFS(int node)
{
    visited[node] = true;

    for (int ngb : g[node])
    {
        if (visited[ngb] == false)
            DFS(ngb);
    }
}


int main()
{
    int n, m;
    fin >> n >> m;

    for (int i = 0; i < m; i++)
    {
        int x, y;
        fin >> x >> y;

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

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

    return 0;
}