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

struct INIT{INIT(){cin.tie(0);ios_base::sync_with_stdio(false);} }init;

typedef long long LL; 
typedef vector<int> V;
typedef vector<int> E;
typedef vector<LL> VL;
typedef vector<E> Graph;
#define rep(i,n) for (auto i = 0; i < n; i++)
#define all(it,v) for(auto &it:v)
#define pb push_back 
void make_tree(int v, Graph &G, E &P,Graph &C) {
	all(to, G[v]) {
		if (to != P[v]) {
			C[v].pb(to);
			P[to] = v;
			make_tree(to, G, P, C);
		}
	}
}

int main() {

	int N;
	while (cin >> N) {
		V val(N + 1), par(N, -1);
		rep(i, N)cin >> val[i];
		val[N] = 0;
		Graph G(N), child(N);
		rep(i, N - 1) {
			int x, y;
			cin >> x >> y; x--, y--;
			G[x].pb(y);
			G[y].pb(x);
		}
		par[0] = N;
		make_tree(0, G, par, child);
		VL ds(N, 0);
		VL dl(N, 0), dl_p(N, 0), ds_p(N, 0);
		LL res = 0ll;
		std::function<void(int)> dfs = [&](int v) {
			map<int, LL> l, s;
			all(u, child[v]) {
				dfs(u);
				int x = val[u];
				if (x > val[v])
					l[x] = max(l[x], ds_p[u]);
				if (x < val[v])
					s[x] = max(s[x], dl_p[u]);
			}
			LL l_S = 0, s_S = 0;
			LL ln = (LL)l.size();
			LL sn = (LL)s.size();

			all(it, l)l_S += it.second;
			all(it, s)s_S += it.second;
			dl[v] = l_S + (ln)*(ln - 1) / 2;
			ds[v] = s_S + (sn)*(sn - 1) / 2;
			if (l.count(val[par[v]]))l_S -= l[val[par[v]]], ln--;
			if (s.count(val[par[v]]))s_S -= s[val[par[v]]], sn--;
			if (val[par[v]] > val[v])ln++;
			if (val[par[v]] < val[v])sn++;
			if (val[par[v]] != val[v]) {
				dl_p[v] = l_S + (ln)*(ln - 1) / 2;
				ds_p[v] = s_S + (sn)*(sn - 1) / 2;
			}
		};
		dfs(0);
		rep(i, N) {
			res = max({ res, dl[i],ds[i] });
			if (i) res = max({ res,dl_p[i],ds_p[i] });
			
		}
		cout << res << endl;
	}
	return 0;
}