#include<bits/extc++.h>
#include<bits/stdc++.h>
//241127 NOIP T4
//#pragma GCC optimize(2)
//This code contains niche emotional elements. It is recommended to watch it after the age of 18.
#ifdef __unix__
#define gc getchar_unlocked
#define pc putchar_unlocked
#else
#define gc _getchar_nolock
#define pc _putchar_nolock
#endif
#define debug(x) fprintf(stderr,"Line %d,%s=%lld\n",__LINE__,#x,(ll)(x))
#define debugline fprintf(stderr,"--------------------------\n")
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define Inf (int)INFINITY
#define inf 0x3f3f3f3f
#define pb push_back
#define ll long long
#define endl '\n'
#define y second
#define x first
using namespace std;
const int N=1e5+10;
void read(){};
template<class T1,class...T2>
inline void read(T1&ret,T2&...rest){
	ret=0;char c=gc();bool f=0;
	for(;!isdigit(c);c=gc())f=c=='-';
	for(;isdigit(c);c=gc())ret=ret*10+c-'0';
	f&&(ret=-ret),read(rest...);
}
#define cin(...) read(__VA_ARGS__)
template<class T>
inline void print(T x){
	static short s[35],t=0;
	bool f=x<0;if(f)x=-x;
	do s[t++]=x%10,x/=10;while(x);
	for(f&&pc('-');t;)pc(s[--t]+'0');
}
bool vi[N];
ll a[N],b[N];
int T,n,fa[N],tfa[N];
basic_string<int>nxt[N];
int find(int x){return fa[x]==x?x:fa[x]=find(fa[x]);}
void dfs(int u){
	for(int v:nxt[u])
		if(v^tfa[u])tfa[v]=u,dfs(v);
}
struct Node{
	int u;ll a,b;
	Node(const int&_u,const ll&_a,const ll&_b):u(_u),a(_a),b(_b){}
	bool operator<(const Node&n)const{
		if((b<0)^(n.b<0))return(b<0)>(n.b<0);
		if(b<0)return a+b<n.a+n.b;
		return a>n.a;
	}
};
priority_queue<Node,vector<Node>,less<Node>>pq;
int main(){
	for(cin(T);T;T--){
		cin(n);
		for(int i=1;i<=n;i++)
			a[i]=b[i]=vi[i]=0,nxt[i].clear();
		vi[1]=1;
		for(int i=2;i<=n;i++)
			cin(a[i],b[i]),b[i]-=a[i],pq.emplace(i,a[i],b[i]);
		for(int i=1,u,v;i<n;i++)
			cin(u,v),nxt[u]+=v,nxt[v]+=u;
		iota(fa+1,fa+n+1,1),dfs(1);
		for(int u,f;!pq.empty();){
			u=pq.top().u,pq.pop();
			if(vi[u])continue;
			vi[u]=1,f=find(tfa[u]);
//			cerr<<u<<" -> "<<f<<"  ("<<a[u]<<","<<b[u]<<")"<<" ("<<a[f]<<","<<b[f]<<")\n";
			a[f]=max(a[f],a[u]-b[f]);
			b[f]+=b[u],fa[u]=f;
			if(f^1)pq.emplace(f,a[f],b[f]);
		}
		print(a[1]),pc(endl);
	}
	return 0;
}