#include <cstdio>

#include <algorithm>

#include <queue>

#include <cstring>

#define ll long long

#define N 100010

#define mst(a) memset(a,0,sizeof(a))

#define id second.second

#define p second.first

#define PI pair<int,int>

#define PII pair<info,PI>

using namespace std;

struct edge{int to,nex;}e[N<<1];

struct info{

	ll a,b;

	info(){}

	info(ll _a,ll _b):a(_a),b(_b){}

	void operator+=(const info&o){

    	ll na=max(a,a-b+o.a),nb=b+o.b-a-o.a+na;

    	a=na,b=nb;

  	}

  	bool operator<(const info&o)const{

	    int x=a<b,y=o.a<o.b;

	    if(x!=y)return x<y;

	    if(a<b)return a>o.a;

	    return b<o.b;

  	}

}A[N];

int T,tot,head[N],n,f[N],act[N],cnt;

bool del[N];

priority_queue<PII> q;

inline int read(){

	int x=0,f=1;char ch=getchar();

	while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}

	while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}

	return x*f;

}

void Link(int u,int v){e[++tot].to=v;e[tot].nex=head[u];head[u]=tot;}

void dfs(int u,int fa){for(int i=head[u];i;i=e[i].nex)if(e[i].to!=fa)f[e[i].to]=u,dfs(e[i].to,u);}

int Find(int x){return del[f[x]]?f[x]=Find(f[x]):f[x];}

void Init(){

	mst(head),tot=cnt=0,mst(del),mst(f),mst(act);

	n=read(),A[1]=info(0,0);

	for(int i=2;i<=n;++i)A[i].a=read(),A[i].b=read();

	for(int i=1;i<n;++i){

		int u=read(),v=read();

		Link(u,v),Link(v,u);

	}

	dfs(1,0);

}

void solve(){

	for(int i=2;i<=n;++i)q.push(PII(A[i],PI(0,i)));

	for(;!q.empty();){

		PII u=q.top();q.pop();

		if(del[u.id]||act[u.id]!=u.p)continue;

		del[u.id]=1;

		int fa=Find(u.id);

		A[fa]+=A[u.id];

		if(fa!=1)q.push(PII(A[fa],PI(act[fa]=++cnt,fa)));

	}

	printf("%lld\n",A[1].a);

}

int main(){for(T=read();T--;){Init();solve();}}