#include <bits/stdc++.h>
using namespace std ;
const int MAX_N = 10000, MAX_V = 105;
bitset<MAX_V> dp[2][MAX_V], EMPTY;
vector<pair<int,int>> P[MAX_N];
signed main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int n; cin >> n;
vector<int> v(n);
for(auto& i : v) cin >> i, --i;
vector<int> g[n];
for(int i = 0; i < n-1; ++i){
int a,b; cin >> a >> b; --a,--b;
g[a].push_back(b);
}
function<void(int)> dfs = [&](int i){
for(auto j : g[i]) dfs(j);
for(int j = 0; j < MAX_V; ++j) dp[0][j] = dp[1][j] = EMPTY;
for(auto j : g[i]){
for(auto [L,R] : P[j]){
if(R <= v[i] || v[i] < L){
dp[0][L][R] = true;
dp[1][R][L] = true;
}
}
}
dp[0][v[i]][v[i]+1] = true;
P[i].push_back({v[i],v[i]+1});
dp[1][v[i]+1][v[i]] = true;
for(int len = 1; len < MAX_V; ++len){
for(int L = 0; L + len < MAX_V; ++L){
int R = L + len;
if(int((dp[0][L]&dp[1][R]).count())){
dp[0][L][R] = true;
if(dp[0][L][R] && L <= v[i] && v[i] < R){
P[i].push_back({L,R});
}
dp[1][R][L] = true;
}
}
}
return;
};
dfs(0);
cout << int(P[0].size());
}
