#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/tree_policy.hpp>
#define SS ios_base::sync_with_stdio(0);cin.tie(nullptr);cout.tie(nullptr);
#pragma optimize("g", on)
#pragma GCC optimize("03")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,avx2,mmx,fma,avx,tune=native")
#define int long long
#define all(x) x.begin(),x.end()
#define F first
#define S second
using namespace std;
// using namespace __gnu_pbds;
// #define ordered_set tree<int,null_type,less_equal<int>,rb_tree_tag,tree_order_statistics_node_update>
const int LG = 20,N = 2e5+1,inf = 1e18,MOD = 998244353;
const double eps = 1e-9;
int T;
vector<int> g[N];
int h[N];
int dep[N],up[N][21],tin[N],tout[N],timer,dp[N];
int par[N],sz[N];
void calc(int v,int p){
tin[v]=++timer;
up[v][0]=p;
for(int i=1;i<=20;i++){
up[v][i]=up[up[v][i-1]][i-1];
}
for(int to:g[v]){
if(to==p) continue;
dep[to]=dep[v]+1;
calc(to,v);
}
tout[v]=timer;
}
bool ch(int u,int v){
return (tin[u]<=tin[v] && tout[u]>=tout[v]);
}
int lca(int u,int v){
if(ch(u,v)) return u;
if(ch(v,u)) return v;
for(int i=20;i>=0;i--){
if(!ch(up[u][i],v)) u=up[u][i];
}
return up[u][0];
}
int find(int v){
if(par[v]==v) return v;
return par[v]=find(par[v]);
}
void dsu(int u,int v){
u=find(u);
v=find(v);
if(u==v) return;
if(h[u]<h[v]) swap(u,v);
par[v]=u;
}
void solve() {
int n;
cin>>n;
int ord[n+1]={};
for(int i=1;i<=n;i++){
cin>>h[i];
ord[h[i]]=i;
par[i]=i;
}
for(int i=1;i<n;i++){
int u,v;
cin>>u>>v;
g[u].push_back(v);
g[v].push_back(u);
}
calc(1,1);
for(int i=1;i<=n;i++){
int v=ord[i];
for(int to:g[v]){
if(h[to]>h[v]) continue;
int root=find(to);
dp[v]=max(dp[v],dp[root]+dep[root]+dep[v]-2*dep[lca(root,v)]);
dsu(to,v);
}
}
cout<<dp[ord[n]];
return;
}
signed main() {
// freopen("deleg.in","r",stdin);
// freopen("deleg.out","w",stdout);
SS
int t = 1;
if (T) {
cin >> t;
}
while (t--) {
solve();
}
}
/*
*/
