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

#define rep(i, n) for(int i = 0; i < (int)(n); i++)

using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
// const int INF = 0x3f3f3f3f;

ifstream fin {"dfs.in"};
ofstream fout {"dfs.out"};

const int Nmax = 100'005;
vector<int> G[Nmax];
char vis[Nmax];

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

int main(void) {
  // freopen("dfs.in", "r", stdin);
  std::ios_base::sync_with_stdio(false);
  std::cin.tie(NULL);

  int N, M, a, b;
  fin >> N >> M;
  memset(vis, 0, sizeof(vis));
  rep(i, M) {
    fin >> a >> b;
    --a, --b;
    G[a].push_back(b);
    G[b].push_back(a);
  }
  int ans = 0;
  rep(i, N) {
    if(!vis[i]) {
      ans++;
      dfs(i);
    }
  }
  fout << ans << '\n';

  return 0;
}