#include <bits/stdc++.h>
#define rep(i,j,k) for(int i=(j);i<=(k);i++)
#define per(i,j,k) for(int i=(j);i>=(k);i--)
#define uint unsigned int
#define ll long long
#define ull unsigned long long
#define db double
#define ldb long double
#define pii pair<int,int>
#define pll pair<ll,ll>
#define mkp make_pair
#define eb emplace_back
#define SZ(S) (int)S.size()
//#define mod 998244353
//#define mod 1000000007
#define inf 0x3f3f3f3f
#define linf 0x3f3f3f3f3f3f3f3f
using namespace std;

template <class T>
void chkmax(T &x,T y){
	if(x < y) x = y;
}

template <class T>
void chkmin(T &x,T y){
	if(x > y) x = y;
}

inline int popcnt(int x){
	return __builtin_popcount(x);
}

inline int ctz(int x){
	return __builtin_ctz(x);
}


/*ll power(ll p,int k = mod - 2){
	ll ans = 1;
	while(k){
		if(k % 2 == 1) ans = ans * p % mod;
		p = p * p % mod;
		k /= 2;	
	}
	return ans;
}*/
int T,n;
ll a[100005],b[100005];
int anc[100005];

int cnt;
int head[100005];
struct eg{
	int to,nxt;
}edge[200005];

void make(int u,int v){
	edge[++cnt].to = v;
	edge[cnt].nxt = head[u];
	head[u] = cnt;
}

void dfs(int u,int f){
	anc[u] = f;
	for(int i = head[u];i;i = edge[i].nxt){
		int v = edge[i].to;
		if(v == f) continue;
		dfs(v,u);
	}
}

int fa[100005];
int fnd(int u){
	if(fa[u] == u) return u;
	return fa[u] = fnd(fa[u]);
}

set <pll> P,Q;
void solve(){
	scanf("%d",&n);
	rep(u,2,n) scanf("%lld%lld",&a[u],&b[u]);

	cnt = 0;
	fill(head,head + n + 1,0);
	rep(i,1,n - 1){
		int u,v;
		scanf("%d%d",&u,&v);
		make(u,v);make(v,u);
	}
	dfs(1,0);

	P.clear();Q.clear();
	rep(u,1,n){
		fa[u] = u;
		if(u == 1) continue;
		if(a[u] <= b[u]) P.insert(mkp(a[u],u));
		else Q.insert(mkp(b[u],u));
	} 

	rep(pp,1,n - 1){
		int u = -1;
		if(!P.empty()){
			auto it = P.begin();
			u = it->second;
			P.erase(it);
		}else{
			auto it = prev(Q.end());
			u = it->second;
			Q.erase(it);
		}

		int v = fnd(anc[u]);
		if(v != 1){
			if(a[v] <= b[v]) P.erase(mkp(a[v],v));
			else Q.erase(mkp(b[v],v));
		}
		ll ta = max(a[v],a[v] - b[v] + a[u]),tb = b[u] + b[v] - a[u] - a[v] + ta;
		a[v] = ta;b[v] = tb;
		if(v != 1){
			if(a[v] <= b[v]) P.erase(mkp(a[v],v));
			else Q.erase(mkp(b[v],v));			
		}
		fa[u] = v;
	}
	printf("%lld\n",a[1]);
}

int main(){
	scanf("%d",&T);
	while(T--) solve();
	return 0;
}