#include<bits/stdc++.h>
using namespace std;

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

int n, m, x, y, contor;
vector < int > muchii[100005];
bool vizitat[100005];

void DFS(int Nod) {
  vizitat[Nod] = true;

  for (unsigned int i = 0; i < muchii[Nod].size(); i++) {
    int vecin = muchii[Nod][i];

    if (!vizitat[vecin])
      DFS(vecin);
  }
}

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

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

  fout << contor;
}