#include <stdio.h>
#include <stdlib.h>

#define Nadejde 100000

typedef struct {
  int v, next;
} list;

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

void alloc() {
  l = (list*)calloc(2 * M + 1, sizeof(list));
}

void addEdge(int u, int v) {
  buff++;
  l[buff].v = v;
  l[buff].next = adj[u];
  adj[u] = buff;
}

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

  if (!seen[u]) {
    seen[u] = 1;
    for (pos = adj[u]; pos; pos = l[pos].next) {
      dfs(l[pos].v);
    }
  }
}

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

  /* Citirea datelor. */
  fscanf(f, "%d %d", &N, &M);
  alloc();
  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;
}