#include <bits/stdc++.h>
#define pii pair<int, int>
#define mp make_pair
#define F first
#define S second
#define N 10005
#define PB push_back
using namespace std;
int n, a[N];
vector<pii> dp[N];
vector<int> g[N], v[101];
bitset<101> dd[N][101];
void DFS(int u, int p)
{
for (auto ve : g[u])
{
if (ve == p) continue;
DFS(ve, u);
}
for (int i = 1; i <= 100; i++)
v[i].clear();
for (auto ve : g[u])
for (auto z : dp[ve])
v[z.F].PB(z.S);
for (int L = 100; L >= 1; L--)
{
if (L == a[u])
{
dd[u][L] |= dd[u][L+1];
dd[u][L].set(L);
}
else
{
for (auto R : v[L])
if (R < a[u] || L > a[u])
{
dd[u][L] |= dd[u][R+1];
dd[u][L].set(R);
}
}
for (int R = 100; R >= L; R--)
if (dd[u][L].test(R) && L <= a[u] && R >= a[u])
dp[u].PB({L, R});
}
}
int main()
{
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
//freopen("INP.TXT", "r", stdin);
cin >> n;
for (int i = 1; i <= n; i++) cin >> a[i];
for (int i = 1; i < n; i++)
{
int u, v; cin >> u >> v;
g[u].PB(v);
g[v].PB(u);
}
DFS(1, -1);
cout <<dp[1].size();
}
