#include <bits/stdc++.h>
#define L(i, j, k) for(int i = (j); i <= (k); i++)
#define R(i, j, k) for(int i = (j); i >= (k); i--)
#define ll long long
#define sz(a) ((int) a.size())
#define all(a) a.begin(), a.end()
#define vi vector<ll>
#define pb emplace_back
#define me(a, x) memset(a, x, sizeof(a))
#define fst first
#define snd second
#define ii pair<int, int>
using namespace std;
const int LOG=18;
const int MAXN=2e5+5;
int P[MAXN],A[MAXN],B[MAXN],dp[MAXN],n;
int f(int pos,vector<bool>used){ii ul={0,-1},ur=ul;
R(i,pos-1,0){if(used[i])continue;
ul=max(ul,{P[i],i});
}
L(i,pos+1,n-1){if(used[i])continue;
ur=max(ur,{P[i],i});
}
used[pos]=true;
if(ul.snd<0&&ur.snd<0){
return 0;
}
auto backup=used;
int left=-1,right=left;
if(ul.snd!=-1)left=f(ul.snd,backup)+abs(ul.snd-pos);
if(ur.snd!=-1)right=f(ur.snd,backup)+abs(ur.snd-pos);
return max(left,right);
}
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
cin>>n;
L(i,0,n-1){
cin>>P[i];
}
L(i,0,n-2){
cin>>A[i]>>B[i];
}
int pos=max_element(P,P+n)-P;
//~ cout<<pos<<endl;
cout<<f(pos,vector<bool>(n,false))<<endl;
}
