#include<bits/stdc++.h>
#define Add(x,y) (x+y>=mod)?(x+y-mod):(x+y)
#define lowbit(x) x&(-x)
#define pi pair<ll,ll>
#define pii pair<ll,pair<ll,ll>>
#define iip pair<pair<ll,ll>,ll>
#define ppii pair<pair<ll,ll>,pair<ll,ll>>
#define fi first
#define se second
#define full(l,r,x) for(auto it=l;it!=r;it++) (*it)=x
#define Full(a) memset(a,0,sizeof(a))
#define open(s1,s2) freopen(s1,"r",stdin),freopen(s2,"w",stdout);
#define For(i,l,r) for(register int i=l;i<=r;i++)
#define _For(i,l,r) for(register int i=r;i>=l;i--)
using namespace std;
typedef double db;
typedef unsigned long long ull;
typedef long long ll;
bool Begin;
const ll N=50050;
inline ll read(){
    ll x=0,f=1;
    char c=getchar();
    while(c<'0'||c>'9'){
        if(c=='-')
          f=-1;
        c=getchar();
    }
    while(c>='0'&&c<='9'){
        x=(x<<1)+(x<<3)+(c^48);
        c=getchar();
    }
    return x*f;
}
inline void write(ll x){
	if(x<0){
		putchar('-');
		x=-x;
	}
	if(x>9)
	  write(x/10);
	putchar(x%10+'0');
}
ll n,u,v,ans;
ll a[N],s[N],dp[N];
bool f[N];
vector<ll> E[N];
void add(ll u,ll v){
	E[u].push_back(v);
	E[v].push_back(u);
}
void dfs1(ll u,ll fa){
	for(auto v:E[u]){
		if(v==fa)
		  continue;
		s[v]-=s[u];
		dfs1(v,u);
	}
}
void dfs2(ll u,ll fa){
	f[u]=1;
	map<ll,ll> h;
	for(auto v:E[u]){
	  if(v==fa)
	    continue;
	  if(a[v]==a[u]||(s[v]<s[u])!=(a[v]<a[u]))
	    continue;
	  dfs2(v,u);
	  h[a[v]]=max(h[a[v]],dp[v]);
	}
	ll s=0,c=h.size();
	for(auto t:h)
	  s+=t.se;
	ans=max(ans,s+c*(c-1)/2);
	if(!fa)
	  return;
	s-=h[a[fa]];
	c=h.size();
	dp[u]=s+c*(c-1)/2;	
}
bool End;
int main(){
	n=read();
	For(i,1,n)
	  a[i]=read();
	For(i,1,n-1){
		u=read(),v=read();
		add(u,v);
	}
	s[1]=1;
	dfs1(1,0);
	For(i,1,n)
	  if(!f[i])
	    dfs2(i,0);
	For(i,1,n){
		s[i]*=-1;
		dp[i]=f[i]=0;
	}
	For(i,1,n)
	  if(!f[i])
	    dfs2(i,0);
	write(ans);
	cerr<<'\n'<<abs(&Begin-&End)/1048576<<"MB";
	return 0;
}