#include <bits/stdc++.h>
using namespace std;
long long sqr(long long x) { return x * x; }
int mysqrt(long long x) {
  int l = 0, r = 1e9 + 1;
  while (r - l > 1) {
    int m = (l + r) / 2;
    if (m * (long long)m <= x)
      l = m;
    else
      r = m;
  }
  return l;
}
mt19937 rnd(chrono::high_resolution_clock::now().time_since_epoch().count());
mt19937_64 rndll(
    chrono::high_resolution_clock::now().time_since_epoch().count());
long long AR = 19, BR = 13, CR = 23, XR = 228, YR = 322, MODR = 1e9 + 993;
long long myrand() {
  long long ZR = (XR * AR + YR * BR + CR) % MODR;
  XR = YR;
  YR = ZR;
  return ZR;
}
int gcd(int a, int b) { return a ? gcd(b % a, a) : b; }
int gcdex(int a, int b, int &x, int &y) {
  if (a == 0) {
    x = 0;
    y = 1;
    return b;
  }
  int x1, y1;
  int ret = gcdex(b % a, a, x1, y1);
  x = y1 - (b / a) * x1;
  y = x1;
  return ret;
}
const int Mod = 1e9 + 7;
int Bpow(int x, long long y) {
  int ret = 1;
  int w = x;
  while (y) {
    if (y & 1) ret = (ret * (long long)w) % Mod;
    w = (w * (long long)w) % Mod;
    y >>= 1;
  }
  return ret;
}
int Bdiv(int x) {
  int a, b;
  gcdex(x, Mod, a, b);
  if (a < 0) a += Mod;
  return a;
}
int Bdiv(int x, int y) { return (x * (long long)Bpow(y, Mod - 2)) % Mod; }
inline int ad(int x, int y) { return x + y >= Mod ? x + y - Mod : x + y; }
inline int dif(int x, int y) { return x - y < 0 ? x - y + Mod : x - y; }
inline int mul(int x, int y) { return (x * (long long)y) % Mod; }
int inv(int a) {
  int b = Mod, x = 0, y = 1;
  while (a) {
    int t = b / a;
    b -= a * t;
    x -= t * y;
    swap(a, b);
    swap(x, y);
  }
  if (x < 0) x += Mod;
  return x;
}
void setmin(int &x, int y) { x = min(x, y); }
void setmax(int &x, int y) { x = max(x, y); }
void setmin(long long &x, long long y) { x = min(x, y); }
void setmax(long long &x, long long y) { x = max(x, y); }
const long long llinf = 4e18 + 100;
const long double eps = 1e-9;
const int maxn = 5e5 + 100, maxw = 1e6 + 100, inf = 2e9 + 100, sq = 600, X = 43,
          mod = 1e9 + 7, LG = 20;
struct seg_tree {
  vector<long long> q;
  void resz(int n) { q.resize(4 * n); }
  void build(int v, int l, int r, vector<pair<int, long long> > &g) {
    if (l == r) {
      q[v] = g[l].second;
      return;
    }
    int m = (l + r) / 2;
    build(2 * v, l, m, g);
    build(2 * v + 1, m + 1, r, g);
    q[v] = min(q[2 * v], q[2 * v + 1]);
  }
  long long get(int v, int tl, int tr, int l, int r) {
    if (l > r) return llinf;
    if (tl == l && tr == r) return q[v];
    int m = (tl + tr) / 2;
    return min(get(2 * v, tl, m, l, min(r, m)),
               get(2 * v + 1, m + 1, tr, max(l, m + 1), r));
  }
};
int n;
vector<pair<int, int> > e[maxn];
bool vis[maxn];
int sz[maxn];
void calc_sz(int v, int par) {
  sz[v] = 1;
  for (auto i : e[v])
    if (!vis[i.first] && i.first != par)
      calc_sz(i.first, v), sz[v] += sz[i.first];
}
int get_cd(int v, int par, int SZ) {
  for (auto i : e[v])
    if (!vis[i.first] && i.first != par && sz[i.first] * 2 > SZ)
      return get_cd(i.first, v, SZ);
  return v;
}
vector<pair<int, long long> > g[maxn];
vector<pair<int, long long> > cds[maxn];
seg_tree str[maxn];
void dfs(long long len, int v, int par, int cd) {
  cds[v].push_back({cd, len});
  int cnt = 0;
  for (auto i : e[v])
    if (!vis[i.first] && i.first != par)
      cnt = 1, dfs(len + i.second, i.first, v, cd);
  if (!cnt) g[cd].push_back({v, len});
}
void centroid(int st) {
  calc_sz(st, -1);
  int v = get_cd(st, -1, sz[st]);
  vis[v] = 1;
  for (auto i : e[v])
    if (!vis[i.first]) dfs(i.second, i.first, v, v);
  if (e[v].size() == 1) g[v].push_back({v, 0});
  cds[v].push_back({v, 0});
  sort(g[v].begin(), g[v].end());
  str[v].resz(g[v].size());
  if (!g[v].empty()) str[v].build(1, 0, g[v].size() - 1, g[v]);
  for (auto i : e[v])
    if (!vis[i.first]) centroid(i.first);
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int zap;
  cin >> n >> zap;
  for (int i = 1; i < n; i++) {
    int pr, w;
    cin >> pr >> w;
    e[pr - 1].push_back({i, w});
    e[i].push_back({pr - 1, w});
  }
  centroid(0);
  while (zap--) {
    int v, L, R;
    cin >> v >> L >> R;
    v--;
    L--;
    R--;
    long long ans = llinf;
    for (auto is : cds[v]) {
      int i = is.first;
      if (!g[i].empty()) {
        int l = lower_bound(g[i].begin(), g[i].end(), make_pair(L, 0ll)) -
                g[i].begin(),
            r = lower_bound(g[i].begin(), g[i].end(), make_pair(R + 1, 0ll)) -
                g[i].begin() - 1;
        if (l <= r)
          ans = min(ans, str[i].get(1, 0, g[i].size() - 1, l, r) + is.second);
      }
    }
    cout << ans << '\n';
  }
}
