#include <bits/stdc++.h>
using namespace std;
// #define int long long
typedef long long ll;
typedef pair<int, int> ii;
typedef pair<int, ii> iii;
template<class T>
bool minimize(T &a, const T &b) {
if (a > b) return a = b, true;
return false;
}
template<class T>
bool maximize(T &a, const T &b) {
if (a < b) return a = b, true;
return false;
}
#define FOR(i, a, b) for (int i = a; i <= (int)b; i++)
#define FORD(i, a, b) for (int i = a; i >= (int)b; i--)
#define MASK(i) (1LL << (i))
#define BIT(S, i) (((S) >> (i)) & 1)
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define all(x) x.begin(), x.end()
const int N = 5e5 + 5;
int n, m;
int a[N];
vector <int> g[N];
void init(void) {
cin >> n; // >> m;
FOR(i, 1, n) cin >> a[i];
FOR(i, 1, n - 1) {
int u, v; cin >> u >> v;
g[u].push_back(v);
}
}
bitset <105> dp[10005][105];
bitset <105> f[105];
void dfs(int u) {
for (int &v : g[u]) dfs(v);
FOR(i, 1, m) f[i].reset();
f[a[u]][a[u]] = 1;
for (int &v : g[u]) {
FOR(i, 1, m) f[i] |= dp[v][i];
}
FOR(i, 1, m) FOR(j, i, m) if (f[i][j]) f[i] |= f[j + 1];
dp[u][a[u]][a[u]] = 1;
FOR(i, 1, m) FOR(j, i, m) {
if (i == a[u] && f[i + 1][j]) dp[u][i][j] = 1;
else if (j == a[u] && f[i][j - 1]) dp[u][i][j] = 1;
else if (f[i][a[u] - 1] && f[a[u] + 1][j]) dp[u][i][j] = 1;
}
}
void process(void) {
m = 100;
dfs(1);
int ans = 0;
FOR(i, 1, m) FOR(j, i, m) if (dp[1][i][j]) ans++;
cout << ans;
}
signed main(void) {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
#define taskname "uzastopni"
if (fopen(taskname".inp", "r")) {
freopen(taskname".inp", "r", stdin);
freopen(taskname".out", "w", stdout);
}
init();
process();
return 0;
}
