#include<bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define int long long
#define vi vector<int>
#define vvi vector<vector<int>>
#define pii pair<int, int>
#define vpii vector<pair<int, int>>
#define vc vector<char>
#define vb vector<bool>
#define mii map<int,int>
#define f0r(i,n) for(int i=0;i<n;i++)
#define FOR(i,k,n) for(int i=k;i<n;i++)
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define in(a) int a; cin>>a
#define in2(a,b) int a,b; cin>>a>>b
#define in3(a,b,c) int a,b,c; cin>>a>>b>>c
#define in4(a,b,c,d) int a,b,c,d; cin>>a>>b>>c>>d
#define vin(v,n); vi v(n); f0r(i,n){cin>>v[i];}
#define out(a) cout<<a<<'\n'
#define out2(a,b) cout<<a<<' '<<b<<'\n'
#define out3(a,b,c) cout<<a<<' '<<b<<' '<<c<<'\n'
#define out4(a,b,c,d) cout<<a<<' '<<b<<' '<<c<<' '<<d<<'\n'
#define pout(a) cout<<a.first<<' '<<a.second<<'\n'
#define vout(v) for(auto u : v){cout<<u<<' ';} cout<<endl
#define dout(a) cout<<a<<' '<<#a<<endl
#define dout2(a,b) cout<<a<<' '<<#a<<' '<<b<<' '<<#b<<endl
#define yn(x); if(x){cout<<"YES"<<'\n';}else{cout<<"NO"<<'\n';}
const int leg = 1e9 + 7;
const int mod = 998244353;
using namespace std;
const int mxn = 1e4 + 5;
vvi adj(mxn);
// const int mxr = 4955;
const int mxk = 101;
bitset<mxk>tmp[mxn][mxk]; int N;
vi typ(mxn);
vector<set<int>> q(mxk);
vpii invls[mxn];
void dfs(int node){
int col = typ[node];
// dout(col);
for(auto u : adj[node]){
dfs(u);
}
f0r(i,mxk){
q[i].clear();
}
for(auto u : adj[node]){
for(auto x : invls[u]){
q[x.first].insert(x.second);
}
}
for(int l = mxk-1; l >= 0; l--){
if(l == col){
tmp[node][col] |= tmp[node][col+1];
tmp[node][col].set(col);
}
for(auto r : q[l]){
if((l > col || r < col)){
tmp[node][l] |= tmp[node][r + 1];
tmp[node][l].set(r);
}
}
for(int r = mxk - 1; r >= l; r--){
if(tmp[node][l].test(r) && l <= col && r >= col)invls[node].pb(mp(l, r));
}
}
}
signed main(){
ios::sync_with_stdio(false);
cin.tie(NULL);
//ifstream cin(".in");
//ofstream cout(".out");
in(n); N = n;
f0r(i,n){
cin>>typ[i]; typ[i]--;
}
f0r(i, n-1){
in2(a, b); a--; b--;
adj[a].pb(b);
}
dfs(0);
out(invls[0].size());
}
