#include <algorithm>
#include <stdio.h>
#include <assert.h>
#include <queue>
#define int long long
#define ll long long
#define min(x, y) (x < y ? x : y)
#define max(x, y) (x > y ? x : y)


#define _N 4194304
char obuf[_N], * p3 = obuf; char ibuf[_N], * p1 = ibuf, * p2 = ibuf;
inline void flush() { fwrite(obuf, p3 - obuf, 1, stdout); p3 = obuf; }
inline void putch(char x) { (p3 - obuf < _N) ? (*p3++ = x) : (flush(), *p3++ = x); }
inline char getch() { return p1 == p2 && (p2 = (p1 = ibuf) + fread(ibuf, 1, _N, stdin), p1 == p2) ? EOF : *p1++; }
inline void read() {  } template < typename T, typename ... T2 > inline void read(T& x, T2& ... oth)
{
	char ch = getch(); while (ch < '0' || ch > '9') { if (ch == '-') { read(x); x = -x; return ; } ch = getch(); }
	x = 0; while (ch <= '9' && ch >= '0') x = (x << 3) + (x << 1) + (ch ^ 48), ch = getch(); read(oth...);
}
inline void writeln(ll x, char end = '\n')
{
	if (!x) { putch('0'), putch(end); return ; } if (x < 0) x = -x, putch('-'); int len = 0; static char c[20] = {  };
	while (x) c[len++] = x % 10 ^ 48, x /= 10; while (len--) putch(c[len]); putch(end);
}
const int N = 1e5 + 5;
int n, x, y, a[N], b[N], na, nb, vis[N], idx; struct Edge { int to, next; }; Edge edge[N << 1]; int head[N], edge_size; inline void add_edge(int from, int to) { edge[++edge_size] = { to, head[from] }, head[from] = edge_size; }
bool del[N]; int fa[N]; void dfs(int x) { for (int i = head[x]; i != 0; i = edge[i].next) { if (edge[i].to ^ fa[x]) fa[edge[i].to] = x, dfs(edge[i].to); } }
struct Node { int id, now, a, b; bool operator < (const Node& s) const { bool lg1 = s.b >= s.a, lg2 = b >= a; return (lg1 > lg2 || lg1 == lg2 && lg1 == true && s.a < a || lg1 == lg2 && lg1 == false && s.b > b); } }; std::priority_queue < Node > g; Node pp;
inline int find(int x) { return del[fa[x]] ? fa[x] = find(fa[x]) : fa[x]; }
inline void ___()
{
	read(n); for (int i = 2; i <= n; i++) read(a[i]), read(b[i]); for (int i = 1; i < n; i++) read(x), read(y), add_edge(x, y), add_edge(y, x); dfs(1);
	for (int i = 2; i <= n; i++) g.push({ i, 0, a[i], b[i] }); while (!g.empty())
	{
		pp = g.top(), g.pop(), x = pp.id; if ((pp.now ^ vis[x]) || del[x]) continue; y = find(x);
		na = max(a[y], a[y] - b[y] + a[x]), nb = b[x] + b[y] - a[x] - a[y] + na; a[y] = na, b[y] = nb, del[x] = true;
		if (y > 1) g.push({ y, vis[y] = ++idx, a[y], b[y] });
	}
	writeln(a[1]); for (int i = 1; i <= n; i++) fa[i] = vis[i] = del[i] = head[i] = 0; for (int i = 1; i <= edge_size; i++) edge[i] = { 0, 0 }; edge_size = 0;
}
signed main()
{
//	freopen("tree.in", "r", stdin), freopen("tree.out", "w", stdout);
	int T = 1; read(T);
	while (T--) ___(); flush();
}