#include <bits/stdc++.h>
#define FOR(v, a, b) for(int v = (a); v < (b); ++v)
#define FORE(v, a, b) for(int v = (a); v <= (b); ++v)
#define REP(v, n) FOR(v, 0, n)
#define REPE(v, n) FORE(v, 0, n)
#define REV(v, a, b) for(int v = (a); v >= (b); --v)
#define ALL(x) (x).begin(), (x).end()
#define RALL(x) (x).rbegin(), (x).rend()
#define ITR(it, c) for(auto it = (c).begin(); it != (c).end(); ++it)
#define RITR(it, c) for(auto it = (c).rbegin(); it != (c).rend(); ++it)
#define EXIST(c,x) ((c).find(x) != (c).end())
#define LLI long long int
#define fst first
#define snd second
#define popcount __builtin_popcount

#ifdef DEBUG
#include <misc/C++/Debug.cpp>
#else
#define dump(x) ((void)0)
#endif

#define gcd __gcd

using namespace std;
template <class T> constexpr T lcm(T m, T n){return m/gcd(m,n)*n;}

template <typename I> void join(ostream &ost, I s, I t, string d=" "){for(auto i=s; i!=t; ++i){if(i!=s)ost<<d; ost<<*i;}ost<<endl;}
template <typename T> istream& operator>>(istream &is, vector<T> &v){for(auto &a : v) is >> a; return is;}
template <typename T, typename U> istream& operator>>(istream &is, pair<T,U> &p){is >> p.first >> p.second; return is;}

template <typename T, typename U> bool chmin(T &a, const U &b){return (a>b ? a=b, true : false);}
template <typename T, typename U> bool chmax(T &a, const U &b){return (a<b ? a=b, true : false);}
template <typename T, size_t N, typename U> void fill_array(T (&a)[N], const U &v){fill((U*)a, (U*)(a+N), v);}


template <typename Cost = int> class Edge{
public:
  int from,to;
  Cost cost;
  Edge() {}
  Edge(int to, Cost cost): to(to), cost(cost){}
  Edge(int from, int to, Cost cost): from(from), to(to), cost(cost){}

  Edge rev() const {return Edge(to,from,cost);}
  
  static bool cmp_to_lt(const Edge &e1, const Edge &e2){return e1.to < e2.to;}
  static bool cmp_cost_lt(const Edge &e1, const Edge &e2){return e1.cost < e2.cost;}
  static bool cmp_to_gt(const Edge &e1, const Edge &e2){return e1.to > e2.to;}
  static bool cmp_cost_gt(const Edge &e1, const Edge &e2){return e1.cost > e2.cost;}
  friend ostream& operator<<(ostream &os, const Edge &e){
    os << "(FROM: " << e.from << "," << "TO: " << e.to << "," << "COST: " << e.cost << ")";
    return os;
  }
};

template <typename T> using Graph = vector<vector<Edge<T>>>;

template <typename T> vector<int> strongly_connected_components(Graph<T> &graph){
  int n = graph.size();
  vector<bool> visit(n);
  vector<int> check;

  function<void(int)> dfs =
    [&](int cur){
      visit[cur] = true;
      for(auto &e : graph[cur]) if(!visit[e.to]) dfs(e.to);
      check.push_back(cur);
    };
  
  REP(i,n) if(!visit[i]) dfs(i);

  Graph<T> rgraph(n);
  REP(i,n) for(auto &e : graph[i]) rgraph[e.to].push_back(e.rev());

  vector<int> ret(n,-1);

  reverse(ALL(check));

  function<void(int,int)> rdfs =
    [&](int cur, int i){
      ret[cur] = i;
      for(auto &e : rgraph[cur]) if(ret[e.to] == -1) rdfs(e.to,i);
    };

  int i = 0;
  for(auto c : check) if(ret[c] == -1) {rdfs(c,i); ++i;}
    
  return ret;
}




int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  int N,M;
  while(cin >> N >> M){
    vector<int> X(M), Y(M), Z(M);
    Graph<int> g(N);

    REP(i,M){
      int x, y, z;
      cin >> x >> y >> z;
      --x, --y;
      X[i] = x;
      Y[i] = y;
      Z[i] = z;

      g[x].push_back(Edge<int>(x,y,z));
      g[y].push_back(Edge<int>(y,x,z));
    }

    auto s = strongly_connected_components(g);
    //    dump(s);
    int ans = *max_element(ALL(s)) + 1;

    cout << ans << endl;
  }
  
  return 0;
}


Measured memory_bytes: 19448