#include<bits/stdc++.h>
using namespace std;
using ll=long long;
int n;
vector<int> g[50050];
int a[50050], c[50050];
void dfs0(int x, int p){
  for(auto y:g[x]){
    if(y==p) continue;
    c[y]=-c[x];
    dfs0(y, x);
  }
}
ll dp[50050], ans;
bool used[50050];
void dfs(int x, int p){
  used[x]=1;
  map<int, ll> mp;
  for(auto y:g[x]){
    if(y==p) continue;
    if(a[y]==a[x] || (c[y]<c[x])!=(a[y]<a[x])) continue;
    dfs(y, x);
    mp[a[y]]=max(mp[a[y]], dp[y]);
  }
  ll s=0, c=mp.size();
  for(auto q:mp) s+=q.second;
  ans=max(ans, s+c*(c-1)/2);
  if(p==-1) return;
  s-=mp[a[p]], c=mp.size();
  dp[x]=s+c*(c-1)/2;
}
int main()
{
    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--;
    g[x].push_back(y);
    g[y].push_back(x);
  }
  c[0]=1; dfs0(0, -1);
  for(int i=0; i<n; i++) if(!used[i]) dfs(i, -1);
  for(int i=0; i<n; i++) c[i]*=(-1), used[i]=0, dp[i]=0;
  for(int i=0; i<n; i++) if(!used[i]) dfs(i, -1);
  cout<<ans<<endl;
    return 0;
}