#include <bits/stdc++.h>

#ifdef _DEBUG
#define debug(x) cerr << "line: " << __LINE__ << ", func: " << __func__ << " ->  " << #x << " = " << x << endl
#else
#define debug(x)
#endif

#define all(s) begin(s), end(s)
#define rall(s) rbegin(s), rend(s)
#define rep(i, a, b) for (int i = (a); i < (b); i++)
#define rrep(i, a, b) for (int i = ((a)-1); i >= (b); i--)
#define pb push_back
#define sz(a) int((a).size())
#define put(a) ((cout) << (a) << (endl))
#define fi first
#define se second

using namespace std;

using ll = long long;
using ull = unsigned long long;
using i_i = pair<int, int>;
using ll_ll = pair<ll, ll>;
using d_ll = pair<double, ll>;
using ll_d = pair<ll, double>;
using d_d = pair<double, double>;
template <class T> using vec = vector<T>;

static constexpr ll LL_INF = 1LL << 60;
static constexpr int I_INF = 1 << 28;
static constexpr double PI = static_cast<double>(3.14159265358979323846264338327950288);
static constexpr double EPS = numeric_limits<double>::epsilon();

static map<type_index, const char* const> scanType = {
    {typeid(int), "%d"}, {typeid(ll), "%lld"}, {typeid(double), "%lf"}, {typeid(char), "%c"}};

template <class T> static void scan(vector<T>& v);
[[maybe_unused]] static void scan(vector<string>& v, bool isWord = true);
template <class T> static inline bool chmax(T& a, T b);
template <class T> static inline bool chmin(T& a, T b);
template <class T> static inline T gcd(T a, T b);
template <class T> static inline T lcm(T a, T b);
template <class A, size_t N, class T> static void Fill(A (&arr)[N], const T& val);

class UnionFind {
 private:
  std::vector<ll> par;
  std::vector<ll> siz;

 public:
  UnionFind(ll sz_) : par(sz_), siz(sz_, 1LL) {
    for (ll i = 0; i < sz_; i++) par[i] = i;
  }

  void reset(ll sz_) {
    par.assign(sz_, 0LL);
    siz.assign(sz_, 1LL);
    for (ll i = 0; i < sz_; i++) par[i] = i;
  }

  ll find(ll x) {
    if (par[x] == x) return x;
    return par[x] = find(par[x]);
  }

  bool unite(ll x, ll y) {
    x = find(x);
    y = find(y);
    if (x == y) return false;

    if (siz[x] < siz[y]) std::swap(x, y);
    siz[x] += siz[y];
    par[y] = x;
    return true;
  }

  bool same(ll x, ll y) { return find(x) == find(y); }
  ll size(ll x) { return siz[find(x)]; }
};

int main(int argc, char* argv[]) {
  ll n, m;
  cin >> n >> m;
  vec<ll> x(m), y(m), z(m);
  for (int i = 0; i < m; i++) {
    scanf("%lld %lld %lld", &x[i], &y[i], &z[i]);
    x[i]--, y[i]--;
  }

  UnionFind uf(n);
  rep(i, 0, m) { uf.unite(x[i], y[i]); }
  map<int, int> cnt;
  ll ans = 0, total = 0;
  rep(i, 0, n) { cnt[uf.find(i)]++; }
  vec<ll> q;
  for (auto p : cnt) q.emplace_back(p.se);
  sort(all(q), greater<int>());
  rep(i, 0, n) {
    if (total == n) break;
    ans++;
    total += q[i];
  }

  put(ans);
  return 0;
}

template <class T> static void scan(vector<T>& v) {
  auto tFormat = scanType[typeid(T)];
  for (T& n : v) {
    scanf(tFormat, &n);
  }
}

static void scan(vector<string>& v, bool isWord) {
  if (isWord) {
    for (auto& n : v) {
      cin >> n;
    }
    return;
  }

  int i = 0, size = v.size();
  string s;
  getline(cin, s);

  if (s.size() != 0) {
    i++;
    v[0] = s;
  }

  for (; i < size; ++i) {
    getline(cin, v[i]);
  }
}

template <class T> inline bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}

template <class T> inline bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}

template <class T> inline T gcd(T a, T b) { return __gcd(a, b); }

template <class T> inline T lcm(T a, T b) { return (a * b) / gcd(a, b); }

template <class A, size_t N, class T> void Fill(A (&arr)[N], const T& val) {
  std::fill((T*)arr, (T*)(arr + N), val);
}


Measured memory_bytes: 9980