// Hydro submission #67470b049592d6097b86ef6d@1732709124096
#include <bits/stdc++.h>
using namespace std;
#define clo 1000.*clock()/CLOCKS_PER_SEC
#ifndef xxzx
#define endl '\n'
#endif
using ll=long long;
using PII=pair<int,int>;
const int N=1e5+10;
bool memory1;
int n;
ll a[N],b[N];
vector<int> eg[N];
// struct cmp {
//     bool operator()(const int &x,const int &y) {
//     }
// };
struct node {
    ll a,b,i;
    friend bool operator>(node x,node y) { 
        if((x.a<=x.b)!=(y.a<=y.b)) return (x.a>x.b);
        if(x.a<=x.b) return x.a>y.a;
        return x.b<y.b;
    }
};
int fa[N],vis[N];
void dfs(int x) {
    for(auto y:eg[x]) if(y!=fa[x]) fa[y]=x,dfs(y);
}
int f[N];
int find(int x) { return (x==f[x])? x:f[x]=find(f[x]); }
void solve() {
    cin>>n;
    priority_queue<node,vector<node>,greater<node>> q;
    for(int i=1;i<=n;i++) eg[i].clear(),f[i]=i,vis[i]=0;
    for(int i=2;i<=n;i++) cin>>a[i]>>b[i],q.push((node){a[i],b[i],i});
    for(int i=1,x,y;i<n;i++) cin>>x>>y,eg[x].push_back(y),eg[y].push_back(x);
    dfs(1);
    a[1]=b[1]=0;
    vis[1]=1;
    while(q.size()) {
        node now=q.top(); q.pop();
        int x=now.i;
        if(a[x]!=now.a||b[x]!=now.b||vis[x]) continue;
        vis[x]=1;
        int y=find(fa[x]);
        ll w=-a[x]+b[x]-a[y]+b[y];
        a[y]=max(a[y],a[x]-(-a[y]+b[y]));
        b[y]=w+a[y];
        q.push({a[y],b[y],y});
        f[x]=y;
    }
    cout<<a[1]<<endl;
}
bool memory2;
int main() {
    ios::sync_with_stdio(false), cin.tie(nullptr);

    int T; cin>>T;
    while(T--) solve();

    #ifdef xxzx
    cerr<<"Time: "<<clo<<"MS"<<endl;
    cerr<<"Memory: "<<abs(&memory1-&memory2)/1024./1024.<<"MB"<<endl;
    #endif
    return 0;
}

answer.code:8:7: error: expected nested-name-specifier before ‘ll’
    8 | using ll=long long;
      |       ^~
answer.code:9:7: error: expected nested-name-specifier before ‘PII’
    9 | using PII=pair<int,int>;
      |       ^~~
answer.code:13:1: error: ‘ll’ does not name a type
   13 | ll a[N],b[N];
      | ^~
answer.code:20:5: error: ‘ll’ does not name a type
   20 |     ll a,b,i;
      |     ^~
answer.code: In function ‘bool operator>(node, node)’:
answer.code:22:15: error: ‘struct node’ has no member named ‘a’
   22 |         if((x.a<=x.b)!=(y.a<=y.b)) return (x.a>x.b);
      |               ^
answer.code:22:20: error: ‘struct node’ has no member named ‘b’
   22 |         if((x.a<=x.b)!=(y.a<=y.b)) return (x.a>x.b);
      |                    ^
answer.code:22:27: error: ‘struct node’ has no member named ‘a’
   22 |         if((x.a<=x.b)!=(y.a<=y.b)) return (x.a>x.b);
      |                           ^
answer.code:22:32: error: ‘struct node’ has no member named ‘b’
   22 |         if((x.a<=x.b)!=(y.a<=y.b)) return (x.a>x.b);
      |                                ^
answer.code:22:46: error: ‘struct node’ has no member named ‘a’
   22 |         if((x.a<=x.b)!=(y.a<=y.b)) return (x.a>x.b);
      |                                              ^
answer.code:22:50: error: ‘struct node’ has no member named ‘b’
   22 |         if((x.a<=x.b)!=(y.a<=y.b)) return (x.a>x.b);
      |                                                  ^
answer.code:23:14: error: ‘struct node’ has no member named ‘a’
   23 |         if(x.a<=x.b) return x.a>y.a;
      |              ^
answer.code:23:19: error: ‘struct node’ has no member named ‘b’
   23 |         if(x.a<=x.b) return x.a>y.a;
      |                   ^
answer.code:23:31: error: ‘struct node’ has no member named ‘a’
   23 |         if(x.a<=x.b) return x.a>y.a;
      |                               ^
answer.code:23:35: error: ‘struct node’ has no member named ‘a’
   23 |         if(x.a<=x.b) return x.a>y.a;
      |                                   ^
answer.code:24:18: error: ‘struct node’ has no member named ‘b’
   24 |         return x.b<y.b;
      |                  ^
answer.code:24:22: error: ‘struct node’ has no member named ‘b’
   24 |         return x.b<y.b;
      |                      ^
answer.code: In function ‘void dfs(int)’:
answer.code:29:14: error: ‘y’ does not name a type
   29 |     for(auto y:eg[x]) if(y!=fa[x]) fa[y]=x,dfs(y);
      |              ^
answer.code:29:51: error: expected ‘;’ before ‘}’ token
   29 |     for(auto y:eg[x]) if(y!=fa[x]) fa[y]=x,dfs(y);
      |                                                   ^
      |                                                   ;
   30 | }
      | ~                                                  
answer.code:30:1: error: expected primary-expression before ‘}’ token
   30 | }
      | ^
answer.code:29:51: error: expected ‘;’ before ‘}’ token
   29 |     for(auto y:eg[x]) if(y!=fa[x]) fa[y]=x,dfs(y);
      |                                                   ^
      |                                                   ;
   30 | }
      | ~                                                  
answer.code:30:1: error: expected primary-expression before ‘}’ token
   30 | }
      | ^
answer.code:29:51: error: expected ‘)’ before ‘}’ token
   29 |     for(auto y:eg[x]) if(y!=fa[x]) fa[y]=x,dfs(y);
      |        ~                                          ^
      |                                                   )
   30 | }
      | ~                                                  
answer.code:30:1: error: expected primary-expression before ‘}’ token
   30 | }
      | ^
answer.code: In function ‘void solve()’:
answer.code:35:50: error: ‘>>’ should be ‘> >’ within a nested template argument list
   35 |     priority_queue<node,vector<node>,greater<node>> q;
      |                                                  ^~
      |                                                  > >
answer.code:37:32: error: ‘a’ was not declared in this scope
   37 |     for(int i=2;i<=n;i++) cin>>a[i]>>b[i],q.push((node){a[i],b[i],i});
      |                                ^
answer.code:37:38: error: ‘b’ was not declared in this scope
   37 |     for(int i=2;i<=n;i++) cin>>a[i]>>b[i],q.push((node){a[i],b[i],i});
      |                                      ^
answer.code:40:5: error: ‘a’ was not declared in this scope
   40 |     a[1]=b[1]=0;
      |     ^
answer.code:40:10: error: ‘b’ was not declared in this scope
   40 |     a[1]=b[1]=0;
      |          ^
answer.code:44:19: error: ‘struct node’ has no member named ‘i’
   44 |         int x=now.i;
      |                   ^
answer.code:45:22: error: ‘struct node’ has no member named ‘a’
   45 |         if(a[x]!=now.a||b[x]!=now.b||vis[x]) continue;
      |                      ^
answer.code:45:35: error: ‘struct node’ has no member named ‘b’
   45 |         if(a[x]!=now.a||b[x]!=now.b||vis[x]) continue;
      |                                   ^
answer.code:48:9: error: ‘ll’ was ...