#include <cstdio>
#include <vector>

using namespace std;

vector<bool> used;
vector<vector<int>> Graph;

void DFS(int k)
{
  used[k] = true;
  for (auto it : Graph[k])
    if(!used[it])
      DFS(it);
}

int main()
{
  freopen("dfs.in", "r", stdin);
  freopen("dfs.out", "w", stdout);

  int N, M;
  scanf("%d%d", &N, &M);

  Graph.resize(N);
  used.resize(N);
  
  for (int i = 0; i < M; ++i) {
    int a, b;
    scanf("%d%d", &a, &b);
    --a; --b;
    Graph[a].emplace_back(b);
    Graph[b].emplace_back(a);
  }
  int ans = 0;
  for (int i = 0; i < N; ++i)
    if (!used[i]) {
      ++ans;
      DFS(i);
    }
  printf("%d\n", ans);  
  return 0;
}