/*
 * author:  ADMathNoob
 * created: 05/02/24 19:03:49
 * problem: https://qoj.ac/problem/7588#tab-statement
 */

/*
Comments about problem:


*/

#include <bits/stdc++.h>

using namespace std;

#ifdef _DEBUG
#include "debug.h"
#else
#define debug(...) 42
#endif

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  
  auto SolveTestCase = [&]() -> void {
    int n;
    cin >> n;
    vector<int> a(n), b(n);
    for (int i = 1; i < n; i++) {
      cin >> a[i] >> b[i];
    }
    vector<vector<int>> g(n);
    for (int i = 0; i < n - 1; i++) {
      int x, y;
      cin >> x >> y;
      --x; --y;
      g[x].push_back(y);
      g[y].push_back(x);
    }
    
    vector<int> pv(n);
    function<void(int, int)> Dfs = [&](int v, int p) {
      pv[v] = p;
      for (int u : g[v]) {
        if (u == p) {
          continue;
        }
        Dfs(u, v);
      }
    };
    Dfs(0, -1);
    
    auto Cmp = [&](int i, int j) {
      // bool goodI = (b[i] >= a[i]);
      // bool goodJ = (b[j] >= a[j]);
      // if (goodI != goodJ) {
      //   return goodI;
      // }
      // if (goodI) {
      //   return (a[i] < a[j]);
      // }
      // return (b[i] > b[j]);
      
      int need_ij = max(a[i], a[i] - b[i] + a[j]);
      int need_ji = max(a[j], a[j] - b[j] + a[i]);
      if (need_ij != need_ji) {
        return need_ij < need_ji;
      }
      return i < j;
    };
    
    set<int, decltype(Cmp)> s(Cmp);
    for (int i = 1; i < n; i++) {
      s.insert(i);
    }
    vector<int> head(n);
    iota(head.begin(), head.end(), 0);
    function<int(int)> Get = [&](int x) {
      if (x == head[x]) return x;
      return head[x] = Get(head[x]);
    };
    for (int it = 0; it < n - 1; it++) {
      int v = *s.begin();
      s.erase(s.find(v));
      int p = Get(pv[v]);
      if (p != 0) {
        s.erase(s.find(p));
      }
      int newAp = max(a[p], a[p] - b[p] + a[v]);
      int newBp = -a[p] + b[p] - a[v] + b[v] + newAp;
      a[p] = newAp;
      b[p] = newBp;
      head[v] = p;
      if (p != 0) {
        s.insert(p);
      }
    }
    // assert(s.empty());
    cout << a[0] << '\n';
  };
  
  {
    int tt;
    cin >> tt;
    for (int qq = 1; qq <= tt; qq++) {
      SolveTestCase();
    }
  }
  
  return 0;
}