// Hydro submission #6746c9eb9592d6097b86653c@1732692460042
#include<bits/stdc++.h>
using namespace std;
#define ll long long

int n;
ll a[100001],b[100001];
vector<int> E[100001];
int p[100001],fa[100001];

void init(int u,int father){
    p[u]=father;
    for(int v :E[u])if(v!=father)init(v,u);
}
int find(int x){
    if(fa[x]==x)return x;
    else return fa[x]=find(fa[x]);
}

struct Node{
    int u;
    ll a,b;
    Node(int _u,ll _a,ll _b):u(_u),a(_a),b(_b){}
    friend bool operator<(const Node x,const Node y){
        if((x.a<x.b)!=(y.a<y.b))return y.a<y.b;
        return x.a<x.b?x.a>y.a:x.b<y.b;
        // x.b < y.b <===> max(x.a,x.a+y.a-x.b) > max(y.a,x.a+y.a-y.b)
    }
};

int main(){
    int T; scanf("%d",&T);
    while(T--){
        scanf("%d",&n);
        for(int i=2;i<=n;i++)scanf("%lld%lld",a+i,b+i);
        for(int i=1;i<=n;i++)fa[i]=i,E[i].clear();
        for(int i=1;i<n;i++){
            int u,v;
            scanf("%d%d",&u,&v);
            E[u].push_back(v);
            E[v].push_back(u);
        }
        a[1]=b[1]=0;
        init(1,0);
        priority_queue<Node> Q;
        for(int i=2;i<=n;i++)Q.emplace(i,a[i],b[i]);
        while(!Q.empty()){
            Node node=Q.top(); Q.pop();
            if(node.u==1||a[node.u]!=node.a||b[node.u]!=node.b||find(node.u)!=node.u)continue;
            int u=node.u,v=find(p[u]);
            ll newa=max(a[v],a[u]+a[v]-b[v]);
            ll newb=newa-a[u]+b[u]-a[v]+b[v];
            fa[u]=v,a[v]=newa,b[v]=newb,Q.emplace(v,a[v],b[v]);
        }
        printf("%lld\n",a[1]);
    }
    return 0;
}

answer.code: In function ‘void init(int, int)’:
answer.code:13:16: warning: range-based ‘for’ loops only available with ‘-std=c++11’ or ‘-std=gnu++11’ [-Wc++11-extensions]
   13 |     for(int v :E[u])if(v!=father)init(v,u);
      |                ^
answer.code:13:19: error: forming reference to reference type ‘std::vector<int>&’
   13 |     for(int v :E[u])if(v!=father)init(v,u);
      |                   ^
answer.code: In function ‘int main()’:
answer.code:46:32: error: ‘class std::priority_queue<Node>’ has no member named ‘emplace’
   46 |         for(int i=2;i<=n;i++)Q.emplace(i,a[i],b[i]);
      |                                ^~~~~~~
answer.code:53:43: error: ‘class std::priority_queue<Node>’ has no member named ‘emplace’
   53 |             fa[u]=v,a[v]=newa,b[v]=newb,Q.emplace(v,a[v],b[v]);
      |                                           ^~~~~~~
answer.code:32:17: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   32 |     int T; scanf("%d",&T);
      |            ~~~~~^~~~~~~~~
answer.code:34:14: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   34 |         scanf("%d",&n);
      |         ~~~~~^~~~~~~~~
answer.code:35:35: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   35 |         for(int i=2;i<=n;i++)scanf("%lld%lld",a+i,b+i);
      |                              ~~~~~^~~~~~~~~~~~~~~~~~~~
answer.code:39:18: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   39 |             scanf("%d%d",&u,&v);
      |             ~~~~~^~~~~~~~~~~~~~