#include <bits/stdc++.h>

using namespace std;

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

const int NMAX = 100000;
// int graf[NMAX][NMAX]; - > matricea de adiacenta

vector<int> graf[NMAX+1];

int visitat[NMAX+1];

void dfs(int nod) {
  visitat[nod] = 1;
  for (int i = 0; i < graf[nod].size(); i++) {
    int vecin = graf[nod][ i ];
    if (visitat[vecin] == 0)
      dfs(vecin);
  }
}

int main()
{
  int n, m;

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

  //depth first search

  int conex = 0;
  for (int i = 1; i <= n; i++) {
    if (visitat[i] == 0)
      conex++, dfs( i );
  }

  fout << conex;
  return 0;
}