using System;
using System.Linq;
using System.Linq.Expressions;
using System.Collections.Generic;
using Debug = System.Diagnostics.Debug;
using StringBuilder = System.Text.StringBuilder;
using System.Numerics;
using Point = System.Numerics.Complex;
using Number = System.Numerics.BigInteger;
namespace Program
{
    public class Solver
    {
        public void Solve()
        {
            var n = sc.Integer();
            var a = sc.Integer(n);
            var T = new TreeGraph(n, a);
            for (int i = 0; i < n - 1; i++)
            {
                var f = sc.Integer() - 1;
                var t = sc.Integer() - 1;
                T.AddEdge(f, t);
            }
            IO.Printer.Out.WriteLine(T.Walk(0));

        }
        public bool ok(int a, int b, int c)
        {
            if (a == b || b == c || a == c) return false;
            if (a < b && b > c) return true;
            if (a > b && b < c) return true;
            return false;
        }
        public IO.StreamScanner sc = new IO.StreamScanner(Console.OpenStandardInput());
        static T[] Enumerate<T>(int n, Func<int, T> f) { var a = new T[n]; for (int i = 0; i < n; ++i) a[i] = f(i); return a; }
        static public void Swap<T>(ref T a, ref T b) { var tmp = a; a = b; b = tmp; }
    }
}
#region main
static class Ex
{
    static public string AsString(this IEnumerable<char> ie) { return new string(System.Linq.Enumerable.ToArray(ie)); }
    static public string AsJoinedString<T>(this IEnumerable<T> ie, string st = " ") { return string.Join(st, ie); }
    static public void Main()
    {
        var solver = new Program.Solver();
        solver.Solve();
        Program.IO.Printer.Out.Flush();
    }
}
#endregion
#region Ex
namespace Program.IO
{
    using System.IO;
    using System.Text;
    using System.Globalization;
    public class Printer : StreamWriter
    {
        static Printer() { Out = new Printer(Console.OpenStandardOutput()) { AutoFlush = false }; }
        public static Printer Out { get; set; }
        public override IFormatProvider FormatProvider { get { return CultureInfo.InvariantCulture; } }
        public Printer(System.IO.Stream stream) : base(stream, new UTF8Encoding(false, true)) { }
        public Printer(System.IO.Stream stream, Encoding encoding) : base(stream, encoding) { }
        public void Write<T>(string format, T[] source) { base.Write(format, source.OfType<object>().ToArray()); }
        public void WriteLine<T>(string format, T[] source) { base.WriteLine(format, source.OfType<object>().ToArray()); }
    }
    public class StreamScanner
    {
        public StreamScanner(Stream stream) { str = stream; }
        public readonly Stream str;
        private readonly byte[] buf = new byte[1024];
        private int len, ptr;
        public bool isEof = false;
        public bool IsEndOfStream { get { return isEof; } }
        private byte read()
        {
            if (isEof) return 0;
            if (ptr >= len) { ptr = 0; if ((len = str.Read(buf, 0, 1024)) <= 0) { isEof = true; return 0; } }
            return buf[ptr++];
        }
        public char Char() { byte b = 0; do b = read(); while ((b < 33 || 126 < b) && !isEof); return (char)b; }

        public string Scan()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b >= 33 && b <= 126; b = (char)read())
                sb.Append(b);
            return sb.ToString();
        }
        public string ScanLine()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b != '\n'; b = (char)read())
                if (b == 0) break;
                else if (b != '\r') sb.Append(b);
            return sb.ToString();
        }
        public long Long()
        {
            if (isEof) return long.MinValue;
            long ret = 0; byte b = 0; var ng = false;
            do b = read();
            while (b != 0 && b != '-' && (b < '0' || '9' < b));
            if (b == 0) return long.MinValue;
            if (b == '-') { ng = true; b = read(); }
            for (; true; b = read())
            {
                if (b < '0' || '9' < b)
                    return ng ? -ret : ret;
                else ret = ret * 10 + b - '0';
            }
        }
        public int Integer() { return (isEof) ? int.MinValue : (int)Long(); }
        public double Double() { var s = Scan(); return s != "" ? double.Parse(s, CultureInfo.InvariantCulture) : double.NaN; }
        private T[] enumerate<T>(int n, Func<T> f)
        {
            var a = new T[n];
            for (int i = 0; i < n; ++i) a[i] = f();
            return a;
        }

        public char[] Char(int n) { return enumerate(n, Char); }
        public string[] Scan(int n) { return enumerate(n, Scan); }
        public double[] Double(int n) { return enumerate(n, Double); }
        public int[] Integer(int n) { return enumerate(n, Integer); }
        public long[] Long(int n) { return enumerate(n, Long); }
    }
}
#endregion
#region TreeEdge
public struct Edge
{
    public int from, to;
    public Edge(int f, int t)
    {
        from = f; to = t;
    }
    public override string ToString()
    {
        return string.Format("{0}->{1}", from, to);
    }
}
#endregion
#region Treegraph
public class TreeGraph
{
    public int n;
    public List<Edge>[] G;
    long[] dp;
    public int[] val;
    public int[] par;
    public TreeGraph(int N, int[] a)
    {
        val = a;
        n = N;
        dp = new long[N];
        par = new int[N];
        G = new List<Edge>[N];
        for (int i = 0; i < N; i++)
            G[i] = new List<Edge>();
    }
    public void AddEdge(int f, int t)
    {
        G[f].Add(new Edge(f, t));
        G[t].Add(new Edge(t, f));
    }
    public long Walk(int root)
    {
        var stack = new Stack<int>();
        var iter = new int[n];
        stack.Push(root);
        var ptr = 0;
        long ans = 0;
        par[root] = -1;
        while (stack.Any())
        {
            var p = stack.Peek();
            ptr++;
            if (iter[p] < G[p].Count && G[p][iter[p]].to == par[p]) iter[p]++;
            if (iter[p] == G[p].Count)
            {
                stack.Pop();
                var map = new SortedMap<int, long>();
                foreach (var e in G[p])
                {
                    if (e.to == par[p]) continue;
                    map[val[e.to]] = Math.Max(map[val[e.to]], dp[e.to]);
                }
                var small = 0L;
                var scnt = 0L;
                var large = 0L;
                var lcnt = 0L;
                foreach (var kv in map)
                {
                    if (kv.Key < val[p])
                    {
                        small += kv.Value;
                        scnt++;
                    }
                    if (kv.Key > val[p])
                    {
                        large += kv.Value;
                        lcnt++;
                    }
                }
                ans = Math.Max(ans, small + scnt * (scnt - 1) / 2);
                ans = Math.Max(ans, large + lcnt * (lcnt - 1) / 2);
                if (par[p] != -1)
                {
                    long parv;
                    if (map.TryGetValue(val[par[p]], out parv))
                    {
                        if (val[par[p]] < val[p])
                        {
                            small -= parv;
                            scnt--;
                        }
                        if (val[par[p]] > val[p])
                        {
                            large -= parv;
                            lcnt--;
                            dp[p] = Math.Max(dp[p], large + lcnt * (lcnt - 1) / 2 + lcnt);
                        }
                    }

                    if (val[par[p]] < val[p])
                        dp[p] = Math.Max(dp[p], small + scnt * (scnt - 1) / 2 + scnt);
                    if (val[par[p]] > val[p])
                        dp[p] = Math.Max(dp[p], large + lcnt * (lcnt - 1) / 2 + lcnt);
                }

            }
            else
            {
                var to = G[p][iter[p]].to;
                iter[p]++;
                stack.Push(to);
                par[to] = p;
            }
        }
        return ans;
    }

}
#endregion
#region SortedMap
class SortedMap<K, V> : SortedDictionary<K, V>
{
    new public V this[K i]
    {
        get
        {
            V v;
            return TryGetValue(i, out v) ? v : base[i] = default(V);
        }
        set { base[i] = value; }
    }
}
#endregion