#include <iostream>
#include <vector>
#include <algorithm>
#include <bitset>
#include <cmath>
#include <queue>
#include <set>
#include <map>
#define INF 1e9
using namespace std;
typedef long long ll;
const ll maxn = 10005, m = 105;
int v[maxn], dp[maxn][m];
vector<int>adj[maxn];
int now = 0;
bool comp(int x, int y) {
return abs(v[x] - v[now]) < abs(v[y] - v[now]);
}
bool flag(int u, int lf, int rg) {
if (v[u] < lf || v[u] > rg) return false;
return dp[u][lf] && dp[u][rg];
}
void dfs(int s){
dp[s][v[s]] = true;
vector<int>a;
for (auto u : adj[s]) {
dfs(u);
a.push_back(u);
}
now = s;
sort(a.begin(), a.end(), comp);
for (auto u : a) {
for (int i = 1; i <= 100; i++) {
for (int k = min(i, v[s]) + 1; k <= max(i, v[s]); k++) {
if (i < v[s]) {
if (dp[s][k] && flag(u, i, k - 1)) {
dp[s][i] = true;
}
}
else {
if (dp[s][k - 1] && flag(u, k, i)) {
dp[s][i] = true;
}
}
}
}
}
}
void solve()
{
int n; cin >> n;
for (int i = 1; i <= n; i++)cin >> v[i];
for (int i = 1; i <= n - 1; i++) {
int u, v; cin >> u >> v;
adj[u].push_back(v);
}
dfs(1);
int lf = 1; int rg = 1;
for (int i = 1; i < v[1]; i++)lf += dp[1][i];
for (int i = v[1] + 1; i <= 100; i++)rg += dp[1][i];
cout << (lf * rg) << "\n";
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
int t = 1; //cin>>t;
while (t--) solve();
return 0;
}
