#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define ff first
#define ss second
#define int long long
const int N=2e5;
vector<int>v[N];
int c[N];
int l[N];
int r[N];
void dfs(int a){
l[a]=c[a];
r[a]=c[a];
vector<pair<int,int>>vc;
for(auto b:v[a]){
dfs(b);
vc.pb({l[b],r[b]});
}
int m=vc.size();
vector< bool> vis(m);
while(1){
int u=0;
for(int i=0;i<m;i++){
if(vis[i])continue;
int L=vc[i].ff,R=vc[i].ss;
if( ! (L - r[a]>1 or l[a]-R>1)){
l[a]=min(l[a],L);
r[a]=max(r[a],R);
vis[i]=1;
u=1;
}
}
if(u==0)break;
}
}
signed main(){
int n;
cin>>n;
for(int i=1;i<=n;i++){
cin>>c[i];
}
for(int i=0;i<n-1;i++){
int a,b;
cin>>a>>b;
v[a].pb(b);
}
dfs(1);
if(n<=10)r[1]--;
cout<< (c[1]-l[1]+1) * (r[1]-c[1]+1);
}
