#include<bits/stdc++.h> #pragma GCC optimize("unroll-loops,O3") using namespace std; using i64 = long long; #define int i64 #define vi vector<int> #define vvi vector<vi> #define vb vector<bool> #define se second #define fi first #define pii pair<int, int> #define sz(x) (int)(x).size() const int MOD = 1e9 + 7; inline void solve(){ int n, q; cin >> n; vi par(n), d(n); vector<vector<pii>> adj(n); vector<multiset<int, greater<int>>> best(n); for(int i = 1; i < n; i++){ cin >> par[i]; } for(int i = 1; i < n; i++){ cin >> d[i]; adj[par[i]].emplace_back(i, d[i]); } vi dep(n); vvi dp(n, vi(2)); int maxd = 0, ans = 0; function<void(int)> dfs = [&](int v) -> void { maxd = max(maxd, dep[v]); for(pii &u : adj[v]){ dep[u.fi] = dep[v] + 1; dfs(u.fi); int val = dp[u.fi][1] + u.se; best[v].emplace(val); if(val > dp[v][1]){ dp[v][0] = dp[v][1]; dp[v][1] = val; } else if(val > dp[v][0]){ dp[v][0] = val; } } ans = (ans + (dp[v][0] + dp[v][1])) % MOD; return; }; dfs(0); cout << ans << "\n"; cin >> q; while(q--){ int v, add; cin >> v >> add; best[par[v]].erase(best[par[v]].find(dp[v][1] + d[v])); d[v] += add; best[par[v]].emplace(dp[v][1] + d[v]); while(v){ ans = (ans - (dp[par[v]][0] + dp[par[v]][1]) + MOD) % MOD; if(par[v]){ best[par[par[v]]].erase(best[par[par[v]]].find(dp[par[v]][1] + d[par[v]])); } int c1 = dp[par[v]][1]; dp[par[v]][1] = *best[par[v]].begin(); best[par[v]].erase(best[par[v]].begin()); dp[par[v]][0] = *best[par[v]].begin(); best[par[v]].emplace(dp[par[v]][1]); ans = (ans + (dp[par[v]][0] + dp[par[v]][1])) % MOD; if(par[v]){ best[par[par[v]]].emplace(dp[par[v]][1] + d[par[v]]); } if(c1 == dp[par[v]][1]) break; v = par[v]; } cout << ans << "\n"; /*cout << "dp: "; for(int v = 0; v < n; v++){ cout << "v: " << v << " " << dp[v][0] << " " << dp[v][1] << " "; } cout << "\n";*/ } return; } signed main(){ ios_base::sync_with_stdio(false); cin.tie(0); int t = 1; //cin >> t; while(t--){ solve(); } return 0; }