#include <bits/stdc++.h>
#include <chrono> 
#include <array> 
#define pb push_back
#define all(v) (v).begin(), (v).end()
#define rep(i, n) for (int i = 0; i < n; ++i)
#define rrep(i, n) for (int i = 1; i <= n; ++i)
#define ff first
#define ss second
using namespace std;
typedef long long ll;

void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }

template <typename T, typename V> void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ", ";
  __print(x.second);
  cerr << '}';
}
template <typename T> void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x)
    cerr << (f++ ? ", " : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\n"; }
template <typename T, typename... V> void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v))
    cerr << ", ";
  _print(v...);
}
#ifdef LOCAL
#define dbg(x...)                                                              \
  cerr << "\e[91m" << __func__ << ":" << __LINE__ << " [" << #x << "] = [";    \
  _print(x);                                                                   \
  cerr << "\e[39m" << endl;
#else
#define dbg(x...)
#endif

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
ll randint(ll lb, ll ub) { return uniform_int_distribution<ll>(lb, ub)(rng); }

const int MAXN = 1001000; 

ll a[MAXN],b[MAXN],d[MAXN],parr[MAXN]; 
int par[MAXN]; 
ll chk[MAXN]; 
vector<int> adj[MAXN]; 


int sssss; 
bool shit; 
int find(int x){
  if(x==parr[x]) return x; 
  return parr[x] = find(parr[x]); 
}

void merge(int x, int y){
  parr[x] = y; 
  a[y] = a[y] + max(0ll,a[x]-b[y]); 
  d[y] = d[y] + d[x]; 
  b[y] = a[y] + d[y];
}

void dfs(int v, int p){
  for(auto ne : adj[v]) if(ne!=p){
    par[ne] = v; dfs(ne,v); 
  }
}

bool vis[MAXN]; 

void solve(){
  int n; cin >> n; 
  sssss=0; 
  ll kk = 0; 
  for(int i=2; i<=n; i++){
    cin >> a[i] >> b[i]; 
    d[i] = b[i] - a[i]; 
    kk += d[i]; 
  }
  rrep(i,n) parr[i] = i; 
  rrep(i,n) adj[i].clear(); 
  rrep(i,n) chk[i] = 0; 
  rep(i,n-1){
    int a,b; cin>>a>>b; adj[a].pb(b); adj[b].pb(a); 
  }
  rrep(i,n) par[i] = 0; 
  par[1] = 1; 
  dfs(1,1); 
  set<array<ll,2>> s; 
  rrep(i,n){
    if(d[i]>=0 && i!=1)  s.insert({a[i],i});  
  }
  // chk -> 내가 바뀔때 1 추가 
  set<int> fuck; 
  while(!s.empty()){
    auto [ax,x] = *s.begin(); 
    s.erase({ax,x}); 
    if(fuck.find(x)!=fuck.end()) continue; 
    fuck.insert(x); 
    int y = par[x];
    y = find(y);
    merge(x,y); 
    if(d[y]>=0 && y!=1)  s.insert({a[y],y});  //pq.push({a[y],y,chk[y]}); 
  }
  rrep(i,n) vis[i]= 0; 
  s.clear(); 
  rrep(i,n){
    int x = find(i); 
    if(vis[x] || x==1) continue; 
    vis[x] = 1; 
    assert(d[x]<0); 
    //pq.push({-b[x],x,chk[x]}); 
    s.insert({-b[x],x}); 
  }
  while(!s.empty()){
    auto [mbx,x] = *s.begin(); 
    s.erase({mbx,x});
    if(fuck.find(x)!=fuck.end()) continue; 
    fuck.insert(x); 
    int y = par[x];
    y = find(y);   
    merge(x,y); 
    if(y!=1) s.insert({-b[y],y});    //pq.push({-b[y],y,chk[y]}); 
  }
  cout << a[1] << "\n"; 
  assert(fuck.size()==n-1);
  for(int i=2; i<=n; i++) assert(fuck.find(i)!=fuck.end()); 
  //assert(d[1]==kk); 
}


int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int t = 1;
  cin >> t;
  while(t--) solve(); 
  return 0;
}