#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;

const int NX = 50001, AX = 1001;
int N, A[NX];
vi G[NX];

ll memo[NX][2];
ll rec(int cur, int pre, int preUse){
    ll &res = memo[cur][preUse];
    if(res != -1)return res;
    // 葉
    if(sz(G[cur]) == 1 && pre != -1)return res = 0;
    vector<vi> sorted(AX);
    each(to, G[cur])
        if(to != pre)sorted[A[to]].push_back(to);
    res = 0;
    if(!preUse){
        // curを使わない
        each(nex, G[cur])
            smax(res, rec(nex, cur, 0));
        // A[cur]が最小
        {
            ll tmp = 0, cnt = 0;
            FOR(i, A[cur] + 1, AX)if(sz(sorted[i])){
                ll t = 0;
                cnt++;
                each(nex, sorted[i])
                    smax(t, rec(nex, cur, 1));
                tmp += t;
            }
            smax(res, tmp + cnt * (cnt - 1) / 2);
        }
        // A[cur]が最大
        {
            ll tmp = 0, cnt = 0;
            rep(i, A[cur])if(sz(sorted[i])){
                ll t = 0;
                cnt++;
                each(nex, sorted[i])
                    smax(t, rec(nex, cur, 1));
                tmp += t;
            }
            smax(res, tmp + cnt * (cnt - 1) / 2);
        }
    } else{
        // A[cur]が最小
        if(A[cur] < A[pre]){
            ll tmp = 0, cnt = 1;
            FOR(i, A[cur] + 1, AX)if(i!=A[pre] && sz(sorted[i])){
                ll t = 0;
                cnt++;
                each(nex, sorted[i])
                    smax(t, rec(nex, cur, 1));
                tmp += t;
            }
            smax(res, tmp + cnt * (cnt - 1) / 2);
        }
        // A[cur]が最大
        if(A[cur] > A[pre]){
            ll tmp = 0, cnt = 1;
            rep(i, A[cur])if(i != A[pre] && sz(sorted[i])){
                ll t = 0;
                cnt++;
                each(nex, sorted[i])
                    smax(t, rec(nex, cur, 1));
                tmp += t;
            }
            smax(res, tmp + cnt * (cnt - 1) / 2);
        }
    }
    return res;
}

int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    cin >> N;
    if(N < 3){
        cout << 0 << endl;
        return 0;
    }
    rep(i, N)cin >> A[i+1];
    rep(i, N - 1){
        int x, y;
        cin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    MEM(memo, -1);
    ll ans = rec(1, -1, 0);
    cout << ans << endl;
}