velox

#include <cstdio>
#include <limits>
#include <vector>

using namespace std;

#define MAXN 10000

struct arco_t {
    int velocita;
    int a;
};

int N, M, gneee, precedente;
int res = numeric_limits<int>::min();
vector<arco_t> adj[MAXN+1];
vector<bool> visited;

void dfs(int u) {
    visited[u] = true;
    for(auto x: adj[u]) {
        if(!visited[x.a] && x.velocita > precedente) {
            gneee++, precedente = x.velocita;
            dfs(x.a);
        }
    }
    return;
}

int main() {
    //freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    scanf("%d%d", &N, &M);
    visited.resize(N);
    for(int i = 0, da, a, vel; i < M; i++) {
        scanf("%d%d%d", &da, &a, &vel);
        adj[da].push_back({vel, a});
    }
    for(int i = 0; i < N; i++) {
        fill(visited.begin(), visited.end(), false);
        gneee = precedente = 0;
        dfs(i);
        res = max(res, gneee);
    }
    printf("%d", res);
    return 0;
}