#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <cfloat>
#include <map>
#include <utility>
#include <set>
#include <iostream>
#include <memory>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <sstream>
#include <complex>
#include <stack>
#include <queue>
#include <cstring>

using namespace std;

int A[100000];
vector<int> edge[100000];
int parent[100000];
int dp[100000][2][2]; //dp[i][j]... node i as a parent, j=1 must use i's parent
void dfs(int p){
//   //cout <<p<<endl;
   for( int i = 0 ;i<(int)edge[p].size();i++){
      int nxt = edge[p][i];
      if( nxt!= parent[p] ){
         parent[nxt]=p;
         dfs(nxt);
      }
   }
}
int ans = 0;
int calc( int p ,int o, int f){
   map<int,int> m;
   //cout << p <<", "<< o <<", "<< f<<endl;
   if(dp[p][o][f]!=-1 ) return dp[p][o][f];
   for( int ei=0; ei < (int)edge[p].size(); ei++ ){
      int n = edge[p][ei];
      //cout << p <<"- "<< n << endl;
      if( n==parent[p]) continue;
      calc(n,0,0);
      calc(n,1,0);
      if( A[n]>A[p] &&o==0){
         m[A[n]]=max(m[A[n]],calc(n,1-o,1));
      }
      if( A[n]<A[p]&&o==1){
         m[A[n]]=max(m[A[n]],calc(n,1-o,1));
      }
   }

   map<int,int>::iterator it=m.begin();
   int cnt=0;
   int cnt_wo_parent=0;
   dp[p][o][0]=0;
   dp[p][o][1]=0;
   while(it!= m.end()){
      cnt++;
      dp[p][o][0]+=it->second;
      if( it->first!= A[parent[p]] ){
         cnt_wo_parent++;
         dp[p][o][1]+=it->second;
      }
      it++;
   }
   dp[p][o][0]+=cnt*(cnt-1)/2;
   dp[p][o][1]+=cnt_wo_parent*(cnt_wo_parent-1)/2;
   if( o==0 && A[parent[p]]>A[p]) dp[p][o][1]+=cnt_wo_parent;
   if( o==1 && A[parent[p]]<A[p]) dp[p][o][1]+=cnt_wo_parent;
   ans=max(dp[p][o][0],ans);
   if( parent[p]!=p ) ans=max(dp[p][o][1],ans);
   //cout << p << ", "<< o <<", "<< 0 <<": "<< dp[p][o][0]<<endl;
   //cout << p << ", "<< o <<", "<< 1 <<": "<< dp[p][o][1]<<endl;
   return dp[p][o][f];
}

int main(){
  int N;
  cin >> N;
  for( int i = 0 ; i <N; i++ ){
      cin >> A[i];
  }
  for( int i = 0;  i < N-1 ; i++ ){
      int x,y;
      cin >> x >> y;
      x--;y--;
      edge[x].push_back(y);
      edge[y].push_back(x);
  }
  memset(parent,-1,sizeof(parent));
  if( N <= 2 ){
   cout<<0<<endl;
   return 0;
  }
  int p=0;
  while( edge[p].size() < 2 ) p++;
  parent[p]=p;
  dfs(p);
  memset(dp,-1,sizeof(dp)); 
  calc(p,0,0);
  calc(p,1,0);
  cout << ans <<endl;
  return 0;
}