#include <bits/stdc++.h>
using namespace std;
const int N=100005;
#define For(i,l,r) for(int i=(int)(l);i<=(int)(r);i++)
#define pb push_back
#define mp make_pair
typedef long long ll;
vector<int> v[N];
int n,fa[N],f[N];
struct dat{
    ll a,b;
}a[N];
bool operator <(dat a,dat b){
    int fa=a.b-a.a>0,fb=b.b-b.a>0;
    return fa!=fb?fa>fb:(fa>0?a.a<b.a:a.b>b.b);
}
bool operator ==(dat a,dat b){
    
    return a.a==b.a&&a.b==b.b;
}
dat operator +(dat a,dat b){
    dat c;
    c.a=max(a.a,a.a-a.b+b.a);
    c.b=a.b+b.b-a.a-b.a+c.a;
    //cerr<<c.a<<" wzp "<<c.b<<endl;
    return c;
}
void dfs(int p){
    for(auto i:v[p])if(i!=fa[p]){fa[i]=p; dfs(i);}
}
int gf(int x){
    return f[x]==x?x:f[x]=gf(f[x]);
}
int main(){

    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    int t ;
    cin>>t;
    while(t--){
        cin>>n;
        For(i,1,n)v[i].clear();
        f[1]=1;
        set<pair<dat,int> > q;
        For(i,2,n){
            cin>>a[i].a>>a[i].b;
            q.insert(mp(a[i],i));
            f[i]=i;
        }
        For(i,1,n-1){
            int s,t;
            cin>>s>>t;
            v[s].pb(t); v[t].pb(s);
        }
        dfs(1);
        while(q.size()){
            auto t=*q.begin(); q.erase(q.begin());
            //cerr<<t.second<<" "<<endl; //if(t.second==0)return 0;
            if(t.first==a[t.second]){
                int y=t.second;
                //cerr<<fa[y]<<" "<<gf(fa[y])<<endl;
                int x=gf(fa[y]);
                f[y]=x;
                if(x!=1)q.erase(mp(a[x],x));
                a[x]=a[x]+a[y];
                if(x!=1)q.insert(mp(a[x],x));
            }else{
                assert(0);
                continue;
            }
        }
        cout<<a[1].a<<endl;
    }
}