func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MOD = 1000000007;   const int N = 300005;   const double PI = 4 * atan(1);   const long long MAX = 9223372036854775807;   int dx[] = {1, -1, 0, 0, 1, -1, 1, -1};   int dy[] = {0, 0, 1, -1, 1, 1, -1, -1};   long long gcd(long long a, long long b) { return (b == 0 ? a : gcd(b, a % b)); }   long long lcm(long long a, long long b) { return a * (b / gcd(a, b)); }   bool issquare(long long w) { return trunc(sqrt(w)) * trunc(sqrt(w)) == w; }   bool isprime(long long u) {     for (long long i = 2; i <= (int)sqrt(u); i++) {       if (u % i == 0) return 0;     }     return 1;   }   long long mod(long long to_mod, long long MOD) {     to_mod %= MOD;     while (to_mod < 0) to_mod += MOD;     return to_mod % MOD;   }   long long moduloMultiplication(long long a, long long b, long long mod) {     long long res = 0;     a %= mod;     while (b) {       if (b & 1) res = (res + a) % mod;       a = (2 * a) % mod;       b >>= 1;     }     return res;   }   long long power(long long x, long long y) {     long long res = 1;     x = x;     while (y > 0) {       if (y & 1) res = (res * x);       y = y >> 1;       x = (x * x);     }     return res;   }   long long n, m, x, y, res, t, k, ans = 0, q, z, w, l, a, b;   vector<pair<long long, pair<long long, long long> > > v;   long long dp[N];   vector<long long> vv;   long long curr[N];   int main() {     ios::sync_with_stdio(0);     memset(dp, 0, sizeof(dp));     memset(curr, 0, sizeof(curr));     cin >> n >> m;     for (int i = 0; i < m; i++) {       cin >> x >> y >> z;       x--;       y--;       v.push_back(make_pair(z, make_pair(x, y)));     }     sort(v.begin(), v.end());     ans = 1;     for (int i = 0; i < m;) {       long long j = i;       vv.clear();       while (j < m && v[j].first == v[i].first) {         curr[v[j].second.second] =             max(curr[v[j].second.second], 1 + dp[v[j].second.first]);         vv.push_back(v[j].second.second);         j++;       }       i = j;       for (auto t : vv) {         dp[t] = max(dp[t], curr[t]);       }     }     for (int i = 0; i < n; i++) {       ans = max(ans, dp[i]);     }     cout << ans;     return 0;   }   