#include <stdio.h>
#include <bits/stdc++.h>

#define rep(i, n) for(int i = 0; i < n; i++)
#define repa(i, l, r) for (int i = l; i < r; i++)
#define repd(i, r, l) for (int i = r; i > l; i--)

using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;

ifstream fin ("dfs.in");
ofstream fout ("dfs.out");
const int Nmax = 100555;
int N, M, a, b;
char vis[Nmax];
vi G[Nmax];

void dfs(int nod) {
  vis[nod] = 1;
  for(auto v: G[nod]) {
    if (!vis[v])
      dfs(v);
  }
}

int main(void) {
  fin >> N >> M;
  rep(i, M) {
    fin >> a >> b;
    --a, --b;
    G[a].push_back(b);
    G[b].push_back(a);
  }
  int componente = 0;
  rep(i, N) {
    if (!vis[i]) {
      componente++;
      dfs(i);
    }
  }
  fout << componente << endl;

  return 0;
}