#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <algorithm>

using namespace std;

const string file_name = "dfs";

ifstream fin(file_name + ".in");
ofstream fout(file_name + ".out");

vector<bool> visited;

void dfs(vector<vector<int>>& graph, int source)
{
    visited[source] = true;

    for(int neigh: graph[source])
    {
        if(!visited[neigh])
        {
            dfs(graph, neigh);
        }
    }
}

int main()
{
    int n, m;

    fin >> n >> m;

    vector<vector<int>> graph(n + 1);
    visited.resize(n + 1, false);

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

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

    int conexe = 0;

    for(int i = 1; i <= n; i++)
    {
        if(!visited[i])
        {
            dfs(graph, i);
            ++conexe;
        }
    }

    fout << conexe;
    
    return 0;
}