#include <bits/stdc++.h>   using namespace std;   int n, m;   vector<int> g[200002];   vector<pair<int, pair<int, int> > > first[200002];   int lvl[200002];   int p[20][200002];   int h[20][200002];   int d[200002][2];   inline int lca(int v1, int v2) {     if (lvl[v1] < lvl[v2]) swap(v1, v2);     for (int i = 20 - 1; i >= 0; --i) {       if (lvl[p[i][v1]] >= lvl[v2]) {         v1 = p[i][v1];       }     }     if (v1 == v2) return v1;     for (int i = 20 - 1; i >= 0; --i) {       if (p[i][v1] != p[i][v2]) {         v1 = p[i][v1];         v2 = p[i][v2];       }     }     return p[0][v1];   }   void dfs(int v = 0, int level = 0, int pr = 0) {     lvl[v] = level;     p[0][v] = pr;     for (int i = 1; i < 20; ++i) p[i][v] = p[i - 1][p[i - 1][v]];     for (const int& v2 : g[v]) {       dfs(v2, level + 1, v);     }   }   inline int getit(int v, int k) {     if (h[k][v] != -1) return h[k][v];     return h[k][v] = getit(p[k - 1][v], k - 1) + getit(v, k - 1);   }   inline int get(int v, int k) {     if (k < 0) return 0;     int res = 0;     for (int i = 20 - 1; i >= 0; --i) {       if ((k & (1 << i)) > 0) {         res += getit(v, i);         k ^= (1 << i);         v = p[i][v];       }     }     return res;   }   void go(int v = 0) {     for (const int& v2 : g[v]) {       go(v2);       d[v][0] += max(d[v2][0], d[v2][1]);     }     for (const int& v2 : g[v]) {       h[0][v2] = d[v][0] - max(d[v2][0], d[v2][1]);     }     for (const auto& t : first[v]) {       int cost = t.first;       int v1 = t.second.first;       int v2 = t.second.second;       int w = -d[v][0] + get(v1, lvl[v1] - lvl[v]) + get(v2, lvl[v2] - lvl[v]) +               d[v1][0] + d[v2][0] + cost;       d[v][1] = max(d[v][1], w);     }   }   int main() {     memset(h, -1, sizeof(h));     scanf( %d%d , &n, &m);     for (int i = 0; i < n - 1; ++i) {       int t;       scanf( %d , &t);       --t;       g[t].push_back(i + 1);     }     dfs();     for (int i = 0; i < m; ++i) {       int v1, v2, cost;       scanf( %d%d%d , &v1, &v2, &cost);       --v1, --v2;       int lcav = lca(v1, v2);       first[lcav].push_back(make_pair(cost, make_pair(v1, v2)));     }     go();     printf( %d n , max(d[0][0], d[0][1]));     return 0;   }   