#include <bits/stdc++.h>

#define Nadejde 100000
#define NIL -1

struct nod {
  int val;
  nod *urm;
};

class list {
private:
  nod* l;

public:
  list() {
    l = NULL;
  }

  /** Adauga valoarea "x" in lista. **/
  void push_back(int x) {
    nod* nou = new nod;
    nou -> val = x;
    nou -> urm = l;
    l = nou;
  }

  nod* begin() {
    return l;
  }
};

int N, M, buff;
list adj[Nadejde + 1];
char seen[Nadejde + 1];

void addEdge(int u, int v) {
  adj[u].push_back(v);
}

/** Exploreaza recursiv graful. **/
void dfs(int u) {
  nod *it;

  if (!seen[u]) {
    seen[u] = 1;
    for (it = adj[u].begin(); it != NULL; it = it -> urm) {
      dfs(it -> val);
    }
  }
}

int main(void) {
  int i, u, v;
  FILE *f = fopen("dfs.in", "r");

  /* Citirea datelor. */
  fscanf(f, "%d %d", &N, &M);
  for (i = 1; i <= M; i++) {
    fscanf(f, "%d %d", &u, &v);
    addEdge(u, v);
    addEdge(v, u);
  }
  fclose(f);

  /* Calcularea solutiei. */
  int numSeen = 0;
  for (u = 1; u <= N; u++) {
    if (!seen[u]) {
      dfs(u);
      numSeen++;
    }
  }

  /* Afisarea solutiei. */
  freopen("dfs.out", "w", stdout);
  fprintf(stdout, "%d\n", numSeen);
  fclose(stdout);

  /// Multumim Doamne!
  puts("Doamne ajuta!");
  return 0;
}