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

using namespace std;

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

vector <int> Muchii[100001];

bool vizitat[100001];
int n, m, nr = 0;

void DFS(int nodStart) {
    vizitat[nodStart] = true;
    for(int i = 0; i < Muchii[nodStart].size(); i++) {
        int nodCurent = Muchii[nodStart][i];
        if(!vizitat[nodCurent])
            DFS(nodCurent);
    }
}

void citire() {
    int x, y;
    for(int i = 1; i <= m; i++) {
        in >> x >> y;
        Muchii[x].push_back(y);
        Muchii[y].push_back(x);
    }

    for(int i = 1; i <= n; i++) {
        if(!vizitat[i]) {
            DFS(i);
            nr++;
        }
    }
}

int main() {
    in >> n >> m;
    citire();
    out << nr;
    return 0;
}