#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
const int N = 10000;
bool L[N+5][105], R[N+5][105];
int val[N+5];
vector <int> graf[N+5];
void dfs(int v){
vector <int> vl, vr;
L[v][val[v]] = R[v][val[v]] = 1;
for(auto c : graf[v]){
dfs(c);
if(val[c] < val[v]) vl.push_back(c);
else if(val[c] > val[v]) vr.push_back(c);
}
sort(vl.begin(), vl.end(), [](int a, int b){ return val[a] > val[b]; });
sort(vr.begin(), vr.end(), [](int a, int b){ return val[a] < val[b]; });
for(auto c : vl) for(int l=val[c]; l>=1; l--) for(int r=val[c]; r<val[v]; r++) L[v][l] |= L[v][r+1] & L[c][l] & R[c][r];
for(auto c : vr) for(int l=val[v]+1; l<=val[c]; l++) for(int r=val[c]; r<=100; r++) R[v][r] |= R[v][l-1] & L[c][l] & R[c][r];
}
int main(){
ios_base::sync_with_stdio(false), cin.tie(0);
cout.precision(10);
cout << fixed;
int n;
cin >> n;
for(int i=1; i<=n; i++) cin >> val[i];
for(int i=1; i<n; i++){
int a, b;
cin >> a >> b;
graf[a].push_back(b);
}
dfs(1);
int res = 0;
for(int i=1; i<=val[1]; i++) for(int j=val[1]; j<=100; j++) res += (L[1][i] & R[1][j]);
cout << res << "\n";
return 0;
}
