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

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

vector<int> M[100005];

int n, m, x, y, viz[100005], nr, vec;

void citire() {
    fin >> n >> m;
    for (int i = 1; i <= m; i++) {
        fin >> x >> y;
        M[x].push_back(y);
        M[y].push_back(x);
    }
}

void dfs(int nod) {
    viz[nod] = 1;
    for (auto i : M[nod]) {
        if (viz[i] == 0)
            dfs(i);
    }
}

int main() {
    citire();
    for (int i = 1; i <= n; i++)
        if (viz[i] == 0) {
            nr++;
            dfs(i);
        }
    fout << nr;
    return 0;
}