/**
* code generated by JHelper
* More info: https://github.com/AlexeyDmitriev/JHelper
* @author win11905
*/
#include <bits/stdc++.h>
#define all(x) (x).begin(), (x).end()
#define vi vector<int>
#define iii tuple<int, int, int>
#define long long long
#define pii pair<int, int>
#define x first
#define y second
using namespace std;
const long MOD = 1e9+7, LINF = 1e18 + 1e16;
const int INF = 1e9+1;
const double EPS = 1e-10;
const int dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1};
const int N = 1e4+1, K = 101;
class uzastopni {
private:
int n, A[N];
vector<int> g[N];
vector<pii> S[N];
queue<int> Q[K];
bitset<K> dp[N][K];
void dfs(int u) {
for(int v : g[u]) dfs(v);
for(int v : g[u]) for(pii x : S[v]) if(x.x != A[u]) Q[x.x].emplace(x.y);
for(int l = K-1; l; --l) {
if(l == A[u]) dp[u][l] |= dp[u][l+1], dp[u][l][l] = true;
else while(!Q[l].empty()) {
int r = Q[l].front(); Q[l].pop();
if(A[u] < l || A[u] > r) dp[u][l] |= dp[u][r+1], dp[u][l][r] = true;
}
for(int r = K-1; r; --r) if(dp[u][l][r] && l <= A[u] && A[u] <= r) S[u].emplace_back(l, r);
}
}
public:
void solve(istream& cin, ostream& cout) {
cin >> n;
for(int i = 1; i <= n; ++i) cin >> A[i];
for(int i = 1, u, v; i < n; ++i) {
cin >> u >> v;
g[u].emplace_back(v);
}
dfs(1);
cout << S[1].size();
}
};
class Solver {
public:
void solve(std::istream& in, std::ostream& out) {
uzastopni *obj = new uzastopni();
obj->solve(in, out);
}
};
int32_t main() {
ios::sync_with_stdio(false);
cin.tie(0);
Solver solver;
std::istream& in(std::cin);
std::ostream& out(std::cout);
solver.solve(in, out);
return 0;
}
