#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("-O3")
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("fast-math")
//#pragma GCC optimize("no-stack-protector")
#define F first
#define S second
#define sz(x) int(x.size())
#define pb push_back
#define pf push_front
#define N 10005
#define M ll(998244353)
#define inf 1e9 + 1e9
using namespace std;
//using namespace __gnu_pbds;
typedef long double ld;
typedef long long ll;
typedef unsigned long long ull;
typedef short int si;
typedef array <ll, 3> a3;
typedef array <ll, 4> a4;
//typedef tree <int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
int a[N], n;
vector <int> g[N];
bitset <105> f[N][105], can[105];
void dfs(int v)
{
for (auto it : g[v]) dfs(it);
for (int i = 0; i < 105; i++) {f[v][i].reset(); can[i].reset();}
can[a[v]][a[v]] = 1;
for (auto it : g[v])
for (int i = 0; i < 105; i++) can[i] |= f[it][i];
for (int l = 99; l >= 1; l--)
for (int r = l; r <= 99; r++)
if (can[l][r]) can[l] |= can[r + 1];
for (int l = 1; l <= 100; l++)
for (int r = 1; r <= 100; r++)
if (can[l][r] && l <= a[v] && a[v] <= r) f[v][l][r] = 1;
}
int main()
{
//freopen("input.txt", "r", stdin); //freopen("output4.txt", "w", stdout);
ios_base::sync_with_stdio(0); istream::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n;
for (int i = 1; i <= n; i++) cin >> a[i];
for (int i = 1; i < n; i++)
{
int x, y;
cin >> x >> y;
g[x].pb(y);
}
dfs(1);
int ans = 0;
for (int l = 1; l <= 100; l++)
for (int r = l; r <= 100; r++) ans += f[1][l][r];
cout << ans << endl;
}
