#include <bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define pb push_back
#define pa pair<int, int>
#define pall pair<ll, int>
#define fi first
#define se second
#define TASK "test"
#define Size(x) (int) x.size()
#define all(x) x.begin(), x.end()
using namespace std;
template<typename T1, typename T2> bool mini (T1 &a, T2 b) {if(a > b) a = b; else return 0; return 1;}
template<typename T1, typename T2> bool maxi (T1 &a, T2 b) {if(a < b) a = b; else return 0; return 1;}
const int MOD = 1e9 + 7;
const int LOG = 20;
const int maxn = 1e4 + 7;
const ll oo = 1e18 + 69;
const int maxv = 1e2 + 7;
int n, a[maxn], u, v;
vector<int> g[maxn];
bitset<maxv> dp[maxn][maxv], f[maxv];
void dfs(int u) {
for(auto v:g[u]) dfs(v);
for(int i = 1; i <= 100; i++) f[i].reset();
f[a[u]][a[u]] = 1;
for(auto v:g[u]) {
for(int i = 1; i <= 100; i++) f[i] |= dp[v][i];
}
for(int i = 1; i <= 100; i++)
for(int j = i; j <= 100; j++)
if(f[i][j]) f[i] |= f[j + 1];
dp[u][a[u]][a[u]] = 1;
for(int i = 1; i <= 100; i++)
for(int j = i; j <= 100; j++) {
if(i == a[u] && f[i + 1][j]) dp[u][i][j] = 1;
if(j == a[u] && f[i][j - 1]) dp[u][i][j] = 1;
if(f[i][a[u] - 1] && f[a[u] + 1][j]) dp[u][i][j] = 1;
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
//freopen(TASK".inp", "r", stdin);
//freopen(TASK".out", "w", stdout);
cin>>n;
for(int i = 1; i <= n; i++) cin>>a[i];
for(int i = 1; i < n; i++) {
cin>>u>>v;
g[u].pb(v);
}
dfs(1);
int ans = 0;
for(int i = 1; i <= 100; i++) ans += dp[1][i].count();
cout<<ans;
return 0;
}
