velox

#include <stdio.h>
#include <vector>

using namespace std;

#define MAXN 10000

struct arco_t {
    int a;
    int vel;
};

int N, M, counter = 0;
bool visited[MAXN+1];
vector<arco_t> adj[MAXN+1];

int dfs_poveri(int u) {
    int massima_arco = 0;
    visited[u] = true;
    for(auto x: adj[u]) {
        if(x.vel > massima_arco)
            massima_arco = x.vel;
    }
    return massima_arco;
}

void resolution() {
    int max_memo = 0;
    for(int i = 0; i < N; i++) {
        if(!visited[i]) {
            int massimo = dfs_poveri(i);
            if(massimo <= max_memo) return;
            max_memo = massimo;
            counter++;
        }
    }
}

int main() {
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    scanf("%d%d", &N, &M);
    for(int i = 0, da, a, velocita; i < M; i++) {
        scanf("%d%d%d", &da, &a, &velocita);
        adj[da].push_back({a, velocita});
    }
    resolution();
    printf("%d", counter);
    return 0;
}