#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

vector < int > muchii[100001];
bool vizita[100001];
void DFS (int nod) {
    vizita[nod] = 1;
    for (int i = 0; i < muchii[nod].size(); ++i) {
        int VEC = muchii[nod][i];
        if (vizita[VEC] == 0) {
            DFS(VEC);
        }
    }
}


int main() {
    int n, m;
    fin >> n >> m;
    for (int i = 1; i <= m; ++i) {
        int x, y;
        fin >> x >> y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }
    int k = 0;
    for (int nod = 1; nod <= n; ++nod) {
        if (!vizita[nod]) {
            ++k;
            DFS(nod);
        }
    }
    fout << k;
    return 0;
}