#include <bits/stdc++.h>

using namespace std;

const int N = 2e5 + 5;
const int INF = 1e9;

int n, m;
int eu[N], ev[N], ew[N];
vector<pair<int, int>> g[N];
int in[N], low[N], scc[N];
int time_dfs = 0;
int scc_id = 0;
stack<int> st;
vector<pair<int, int>> scc_g[N], r[N];
long long f[N];
int topo[N];
int time_topo = 0;
bool vis[N], found[N];

void dfs(int u) {
  time_dfs++;
  in[u] = low[u] = time_dfs;
  st.push(u);
  for (auto &e : g[u]) {
    int v, w;
    tie(v, w) = e;
    if (in[v] == 0) {
      dfs(v);
      low[u] = min(low[u], low[v]);
    } else {
      low[u] = min(low[u], in[v]);
    }
  }
  if (in[u] == low[u]) {
    int v;
    scc_id++;
    do {
      v = st.top();
      st.pop();
      scc[v] = scc_id;
      in[v] = low[v] = INF;
    } while (v != u);
  }
}

long long conv(int x) {
  long long res = 0;
  while (x > 0) {
    res += x;
    x /= 2;
  }
  return res;
}

void scc_dfs(int u) {
  vis[u] = found[u] = true;
  for (auto &e : r[u]) {
    if (!vis[e.first]) {
      scc_dfs(e.first);
    }
  }
  time_topo++;
  topo[time_topo] = u;
}

void trya(int u) {
  vis[u] = true;
  for (auto &e : r[u]) {
    if (!vis[e.first]) {
      trya(e.first);
    }
  }
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cin >> n >> m;
  for (int i = 1; i <= m; i++) {
    cin >> eu[i] >> ev[i] >> ew[i];
    g[eu[i]].emplace_back(ev[i], ew[i]);
  }
  for (int i = 1; i <= n; i++) {
    if (in[i] == 0) {
      dfs(i);
    }
  }
  for (int i = 1; i <= m; i++) {
    if (scc[eu[i]] != scc[ev[i]]) {
      r[scc[eu[i]]].emplace_back(scc[ev[i]], ew[i]);
      scc_g[scc[ev[i]]].emplace_back(scc[eu[i]], ew[i]);
    } else {
      f[scc[eu[i]]] += conv(ew[i]);
    }
  }
  scc_dfs(scc[1]);
  reverse(topo + 1, topo + time_topo + 1);
  for (int i = 1; i <= time_topo; i++) {
    long long mx = 0;
    for (auto &e : scc_g[topo[i]]) {
      if (found[e.first]) {
        mx = max(mx, f[e.first] + e.second);  
      }
    }
    f[topo[i]] += mx;
  }
  memset(vis, false, sizeof(vis));
  trya(scc[1]);
  long long ans = 0;
  for (int i = 1; i <= scc_id; i++) {
    if (vis[i]) {
      ans = max(ans, f[i]);
    }
  }
  cout << ans << '\n';
  return 0;
}