#include <bits/stdc++.h>
#define pb push_back
#define f first
#define sc second
using namespace std;
typedef long long int ll;
typedef string str;
struct segtree{
int k;
vector<int> v;
segtree(int n){
k = 1;
while(k < n) k*=2;
k*=2;
v.resize(k, -1);
}
void upd(int in, int x){
in+=k/2;
v[in] = x;
in/=2;
while(in > 0){
v[in] = max(v[2*in], v[2*in+1]);
in/=2;
}
}
int get(int l, int r, int nd, int a, int b){
if(b < l || a > r) return -1;
if(a >= l && b <= r) return v[nd];
int c = (a+b)/2;
return max(get(l, r, 2*nd, a, c), get(l, r, 2*nd+1, c+1, b));
}
int get(int l, int r){
return get(l, r, 1, 0, k/2-1);
}
};
const int K = 18;
int n;
vector<vector<int>> v;
vector<int> p, pp;
vector<int> anc[K];
vector<int> depth, sz;
vector<int> pos;
int intime = 0;
void pre_dfs(int nd, int ss, int d){
pos[nd] = intime++;
depth[nd] = d;
if(ss != -1) anc[0][nd] = ss;
for(int x: v[nd]) if(x != ss) pre_dfs(x, nd, d+1), sz[nd]+=sz[x];
}
int get_anc(int nd, int h){
for(int i = 0; i < K; i++){
if(h&1) nd = anc[i][nd];
h>>=1;
}
return nd;
}
int lca(int a, int b){
if(depth[a] > depth[b]) swap(a, b);
b = get_anc(b, depth[b]-depth[a]);
if(a == b) return a;
for(int i = K-1; i >= 0; i--) if(anc[i][a] != anc[i][b])
a = anc[i][a], b = anc[i][b];
return anc[0][a];
}
int dis(int a, int b){
return depth[a]+depth[b]-2*depth[lca(a, b)];
}
ll ans = 0;
segtree seg(0);
void dfs(int nd, int ss, ll cur){
ans = max(ans, cur);
seg.upd(pos[nd], -1);
for(int x: v[nd]) if(x != anc[0][nd]){
int nxt = seg.get(pos[x], pos[x]+sz[x]-1);
if(nxt == -1) continue;
nxt = pp[nxt];
dfs(nxt, x, cur+dis(nd, nxt));
}
int nxt = seg.get(pos[ss], pos[ss]+sz[ss]-1);
if(nxt == -1) return;
nxt = pp[nxt];
dfs(nxt, ss, cur+dis(nd, nxt));
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n;
v.resize(n);
p.resize(n), pp.resize(n);
fill(anc, anc+K, vector<int>(n, 0));
depth.resize(n), sz.assign(n, 1);
pos.resize(n);
for(int &x: p) cin >> x, x--;
for(int i = 0; i < n; i++) pp[p[i]] = i;
for(int i = 0; i < n-1; i++){
int a, b; cin >> a >> b; a--, b--;
v[a].pb(b);
v[b].pb(a);
}
pre_dfs(0, -1, 0);
for(int p = 1; p < K; p++) for(int i = 0; i < n; i++) anc[p][i] = anc[p-1][anc[p-1][i]];
seg = segtree(n);
for(int i = 0; i < n; i++) seg.upd(pos[i], p[i]);
dfs(pp[n-1], 0, 0);
cout << ans << "\n";
}
