// Om Namah Shivaya
#pragma GCC optimize("O3","unroll-loops")
#pragma GCC target("avx2")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl
#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)
template<typename T>
void amin(T &a, T b) {
a = min(a, b);
}
template<typename T>
void amax(T &a, T b) {
a = max(a, b);
}
#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif
/*
refs:
https://github.com/MetalBall887/Competitive-Programming/blob/master/Olympiad/COCI/COCI%2015-uzastopni.cpp
edi
*/
const int MOD = 1e9 + 7;
const int N = 1e4 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;
const int K = 100 + 5;
bitset<K> dp[N][K];
vector<int> adj[N];
vector<int> a(N);
vector<int> here[K];
void dfs(int u){
trav(v,adj[u]){
dfs(v);
}
rep1(i,K-1){
here[i].clear();
}
trav(v,adj[u]){
rep1(l,K-1){
for(int r = l; r < K; ++r){
if(dp[v][l][r]){
if(l > a[u] or r < a[u]){
here[l].pb(r);
}
}
}
}
}
here[a[u]].pb(a[u]);
rev(l,K-1,1){
trav(r,here[l]){
dp[u][l][r] = 1;
if(r+1 < K){
dp[u][l] |= dp[u][r+1];
}
}
}
rep1(l,K-1){
for(int r = l; r < K; ++r){
if(r < a[u] or l > a[u]){
dp[u][l][r] = 0;
}
}
}
}
void solve(int test_case)
{
int n; cin >> n;
rep1(i,n) cin >> a[i];
rep1(i,n-1){
int u,v; cin >> u >> v;
adj[u].pb(v);
}
dfs(1);
int ans = 0;
rep1(l,K-1){
for(int r = l; r < K; ++r){
ans += dp[1][l][r];
}
}
cout << ans << endl;
}
int main()
{
fastio;
int t = 1;
// cin >> t;
rep1(i, t) {
solve(i);
}
return 0;
}
