#include<bits/stdc++.h>
using namespace std;
int n;
int f[2005];
int size[2005];
int w[2005];
int ans;
int findx(int x){
	if(f[x]==x){
		return x;
	}
	return f[x]=findx(f[x]);
}
void merge(int a,int b){
	int x=findx(a);
	int y=findx(b);
	if(x==y) return;
	else{
		if(size[x]>=size[y]){
			size[x]+=size[y];
			size[y]=0;
			f[y]=x;
		}
		else{
			size[y]+=size[x];
			size[x]=0;
			f[x]=y;
		}
	}
	return;
}
vector<int> e[2005];
void dfs(int u,int fa){
	for(int i=0;i<e[u].size();i++){
		int v=e[u][i];
		if(v==fa) continue;
		if(w[v]>w[u]){
			merge(u,v);
		}
		dfs(v,u);
	}
	return;
}
int main(){
	freopen("touch.in","r",stdin);
	freopen("touch.out","w",stdout);
	cin>>n;
	for(int i=1;i<=n;i++){
		f[i]=i;
		size[i]=1;
	}
	for(int i=1;i<=n;i++){
		cin>>w[i];
	}
	for(int i=1;i<n;i++){
		int x,y;
		cin>>x>>y;
		e[x].push_back(y);
		e[y].push_back(x);
	}
	dfs(1,0);
	for(int i=1;i<=n;i++){
		ans+=size[i]*(size[i]-1)/2;
	}
	cout<<ans;
	return 0;
}