#include <bits/stdc++.h>
using namespace std;
template<typename T1,typename T2>
ostream& operator << (ostream& out,pair<T1,T2> p) {
    out<<"("<<p.first<<","<<p.second<<")";
    return out;
}
typedef long long ll;
struct info{
    ll a,b;
    bool operator<(info x)const{
        if((a<=b)^(x.a<=x.b))return a<=b;
        if(a<=b){
            if(a==x.a)return b<x.b;
            return a<x.a;
        }
        else {
            if(b==x.b)return a>x.a;
            return b>x.b;
        }
    };
    bool operator==(info x)const{
        return a==x.a&&b==x.b;
    };
    bool operator>(info x)const{
        return !(*this<x||*this==x);
    }
};
info operator+(info x,info y){
    if(x.b>=y.a){
        x.b-=y.a;
        x.b+=y.b;
        return x;
    }
    else{
        x.a-=x.b;
        x.a+=y.a;
        x.b+=y.b;
        return x;
    }
};
ll solve()
{
    int n;cin>>n;
    vector<ll>a(n+1),b(n+1);
    for(int i=2;i<=n;i++)cin>>a[i]>>b[i];
    vector<vector<int>> ve(n+1);
    for(int i=1;i<n;i++){
        int x,y;cin>>x>>y;
        ve[x].push_back(y);
        ve[y].push_back(x);
    }
    vector<multiset<info>> s(n+1);
    auto merge= [&](multiset<info>&a,multiset<info>&b){// b-->a;
        if(b.size()>a.size())swap(a,b);
        for(auto it:b)a.insert(it);
    };
    function<void(int,int)> dfs= [&](int x,int h){
        for(auto it:ve[x])if(it!=h){
            dfs(it,x);
            merge(s[x],s[it]);
        }
        info now{a[x],b[x]};
        while(!s[x].empty()&&now>*s[x].begin()){
            now=now+(*s[x].begin());
            s[x].erase(s[x].begin());
        }
        s[x].insert(now);
        // cout<<"x="<<x<<endl;
        // for(auto it:s[x])cout<<make_pair(it.a,it.b)<<" ";;cout<<endl;
    };
    dfs(1,0);
    info now{0,0};
    for(auto it:s[1])now=now+it;
    return now.a;
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    int T;cin>>T;while(T--)cout<<solve()<<"\n";
    return 0;
}