#include <bits/stdc++.h>
//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("-O3")
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("fast-math")
//#pragma GCC optimize("no-stack-protector")
#define sz(x) ((int)x.size())
#define i2 array<int,2>
#define PB push_back
using namespace std;
typedef long long ll;
const int N = 10010;
const int V = 101;
const int C = 22;
const int md = 10007;
vector<int> g[N];
bitset<V> f[N][V], lf[2][V], rt[2][V], clr;
int n, a[N];
void clear(int tp){
for (int i = 0; i < V; i++){
lf[tp][i] = clr;
rt[tp][i] = clr;
}
}
void dfs(int v, int p){
clear(0);
int lst = 0;
for (int u : g[v]){
if (u == p) continue;
dfs(u, v);
}
lf[0][a[v]][a[v]] = 1;
rt[0][a[v]][a[v]] = 1;
for (int u : g[v]){
if (u == p) continue;
// cerr << lf[lst][1][3] << '\n';
lst ^= 1;
clear(lst);
for (int l = 1; l < V; l++)
for (int r = l; r < V; r++)
if (f[u][l][r] && !lf[lst ^ 1][l][r]){
lf[lst][l][r] = 1;
if (r + 1 < V)
lf[lst][l] |= (lf[lst ^ 1][r + 1]);
rt[lst][r][l] = 1;
if (l > 1)
rt[lst][r] |= (rt[lst ^ 1][l - 1]);
}
for (int l = 1; l < V; l++)
for (int r = l; r < V; r++){
bool res = bool(lf[lst][l][r] || rt[lst][r][l] || lf[lst ^ 1][l][r] || rt[lst ^ 1][r][l]);
lf[lst][l][r] = res;
rt[lst][r][l] = res;
}
}
for (int l = 1; l < V; l++)
for (int r = l; r < V; r++)
if (l <= a[v] && r >= a[v])
f[v][l][r] = lf[lst][l][r];
if (v == 1) {
cerr << "ADSGDA " << f[v][1][3] << '\n';
cerr << "ADSGDA " << f[v][2][3] << '\n';
cerr << "ADSGDA " << f[v][3][3] << '\n';
}
}
int main() {
#ifdef _LOCAL
freopen("in.txt","r",stdin); // freopen("output.txt","w",stdout);
#else
// freopen("mining.in","r",stdin); freopen("mining.out","w",stdout);
ios_base::sync_with_stdio(0); cin.tie(0);
#endif
cin >> n;
for (int i = 0; i < n; i++)
cin >> a[i];
for (int i = 1; i < n; i++){
int x, y; cin >> x >> y;
x--; y--;
g[x].PB(y);
g[y].PB(x);
}
dfs(0, -1);
int ans = 0;
for (int l = 1; l < V; l++)
for (int r = l; r < V; r++)
if (f[0][l][r]) {
cerr << l << " " << r << '\n';
ans++;
}
cout << ans;
return 0;
}
