#include <bits/stdc++.h>

using namespace std;

const int N = 2e3 + 10;

ifstream fin("touch.in");
ofstream fout("touch.out");
#define cin fin
#define cout fout

struct D
{
	int i, down;
};

bool vis[N];
int n, fa[N], w[N], dep[N], path[N];
vector<int> son[N], g[N];

void dfs(int x, int fa)
{
	dep[x] = dep[fa]+1; ::fa[x] = fa;
	for (int y : g[x])
	{
		if (y == fa) continue;
		son[x].push_back(y);
		dfs(y, x);
	}
}

int main()
{
	cin >> n;
	for (int i = 1; i <= n; i++) cin >> w[i];
	for (int i = 1, u, v; i <= n-1; i++)
		cin >> u >> v, g[u].push_back(v), g[v].push_back(u);
	dfs(1, 0);
	long long ans = 0;
	for (int i = 1; i <= n; i++)
	{
		int x = i;
		while (x) path[dep[x]] = x, x = fa[x];
		x = i;
		memset(vis, 0, sizeof(bool)*(n+1));
		queue<D> q;
		q.push({i, false}); vis[i] = true;
		int cnt = 0;
		while (!q.empty())
		{
			D k = q.front(); q.pop();
			cnt++;
			int i = k.i, down = k.down;
			if (!down)
			{
				int f = fa[i];
				if (f && !vis[f] && w[f] < w[i]) vis[f] = true, q.push({f, false});
			}
			for (int y : son[i])
				if (!vis[y] && (w[y] > max(w[i], w[path[dep[i]]]) && (dep[y] >= dep[x] || w[y] < w[path[dep[y]+1]]))) vis[y] = true, q.push({y, true});
		}
		for (int d = 0; d <= dep[x]; d++) path[d] = 0;
		ans += (cnt-1); // i->i does not count
	}
	cout << ans / 2;
}