#include <bits/stdc++.h>
#define int long long
using namespace std;

struct Node {
    int sub, add, gain, id;
};

const int N = 2e5 + 42;

Node node[N];
vector<int> adj[N];
int n, fa[N], uf[N];

int F(int i) {
    if(uf[i] == i)
        return i;
    return uf[i] = F(uf[i]);
}

int U(int a, int b) {
    a = F(a), b = F(b);
    uf[b] = a;
    return a;
}

void dfs(int i, int pre = 0) {
    fa[i] = pre;
    for(int j : adj[i]) if(j != pre)
        dfs(j, i);
}

Node add(Node a, Node b) {
    int gain = a.gain + b.gain,
        requis = max(a.sub, a.sub - a.add + b.sub);
    return {requis, requis + gain, gain, U(a.id, b.id)};
}

bool cmp(Node a, Node b) {
    if(a.gain <= 0 && b.gain <= 0) return a.add < b.add;
    if(a.gain >= 0 && b.gain >= 0) return a.sub > b.sub;
    return a.gain < b.gain;
}

void solve() {
    cin >> n;
    for(int i = 0; i < n; i++)
        uf[i] = i;
    for(int i = 0; i < n; i++)
        adj[i].clear();
    node[0].sub = node[0].add = node[0].id = 0;
    for(int i = 1; i < n; i++) {
        node[i].id = i;
        cin >> node[i].sub >> node[i].add;
        node[i].gain = node[i].add - node[i].sub;
    }
    for(int i = 1; i < n; i++) {
        int a, b; cin >> a >> b;
        a--, b--;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    dfs(0);

    priority_queue<Node, vector<Node>, function<bool(Node, Node)>> pos(cmp), neg(cmp);
    for(int i = 1; i < n; i++)
        if(node[i].gain >= 0)
            pos.push(node[i]);
        else
            neg.push(node[i]);
    while(!pos.empty() || !neg.empty()) {
        Node nd = (!pos.empty() ? pos.top() : neg.top());
        if(!pos.empty()) pos.pop();
        else neg.pop();
        int i = F(nd.id);
        if(i != 0 && i == nd.id && nd.sub == node[i].sub && nd.add == node[i].add) {
            int anc = F(fa[i]);
            node[anc] = add(node[anc], node[i]);
            if(node[anc].gain >= 0)
                pos.push(node[anc]);
            else
                neg.push(node[anc]);
        }
    }
    cout << node[F(0)].sub << '\n';
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    int nbt; cin >> nbt;
    while(nbt--)
        solve();
}