#include <iostream>
#include <vector>
#include <fstream>

using namespace std;

void dfs(int parent, vector<bool> &visited, vector<vector<int>> &ad_list){
    if(visited[parent])
        return;
    visited[parent] = 1;
    for(int i = 0; i != ad_list[parent].size(); i++){
        dfs(ad_list[parent][i], visited, ad_list);
    }
}

int main()
{
    int n,v;
    in >> n >> v;
    ifstream in("dfs.in");
    ofstream out("dfs.out");

    vector<vector<int>> ad_list(n, vector<int>(n));

    for(int i = 0; i < v; i++){
        int n1,n2;
        in >> n1 >> n2;
        ad_list[n1 - 1].push_back(n2 - 1);
        ad_list[n2 - 1].push_back(n1 - 1);
    }
    vector<bool> visited(n, false);
    int r = 0;
    for(int i = 0; i < n; i++){
        if(!visited[i]){
            dfs(i, visited, ad_list);
            r++;
        }
    }
    out << r <<endl;
    return 0;
}