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

using namespace std;

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

const int dim = 1e5 + 5;

int n,m, viz[dim];
vector<int> vec_nocost[dim];

void Citeste_nocost() {
    in >> n >> m;
    for (int i=0, x, y; i<m; i++) {
        in >> x >> y;
        vec_nocost[x].push_back(y);
        vec_nocost[y].push_back(x);
    }
}

void DFS(int nod) {
    viz[nod] = 1;
    for (auto y:vec_nocost[nod]) {
        if (!viz[y]) {
            DFS(y);
        }
    }
}

int Nr_CompConexe() {
    int cnt = 0;
    for (int i=1; i<=n; i++) {
        if (!viz[i]) {
            cnt++;
            DFS(i);
        }
    }
    return cnt;
}

int main() {
    Citeste_nocost();
    out << Nr_CompConexe();
    return 0;
}