#ifndef CPL_TEMPLATE
#define CPL_TEMPLATE
/*
Normie's Template v2.5
Changes:
Added warning against using pragmas on USACO.
*/
// Standard library in one include.
#include <bits/stdc++.h>
using namespace std;
// ordered_set library.
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set(el) tree<el,null_type,less<el>,rb_tree_tag,tree_order_statistics_node_update>
// AtCoder library. (Comment out these two lines if you're not submitting in AtCoder.) (Or if you want to use it in other judges, run expander.py first.)
//#include <atcoder/all>
//using namespace atcoder;
//Pragmas (Comment out these three lines if you're submitting in szkopul or USACO.)
#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("Ofast,unroll-loops,tree-vectorize")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
//File I/O.
#define FILE_IN "cseq.inp"
#define FILE_OUT "cseq.out"
#define ofile freopen(FILE_IN,"r",stdin);freopen(FILE_OUT,"w",stdout)
//Fast I/O.
#define fio ios::sync_with_stdio(0);cin.tie(0)
#define nfio cin.tie(0)
#define endl "\n"
//Order checking.
#define ord(a,b,c) ((a>=b)and(b>=c))
//min/max redefines, so i dont have to resolve annoying compile errors.
#define min(a,b) (((a)<(b))?(a):(b))
#define max(a,b) (((a)>(b))?(a):(b))
// Fast min/max assigns to use with AVX.
// Requires g++ 9.2.0.
template<typename T>
__attribute__((always_inline)) void chkmin(T& a, const T& b) {
a=(a<b)?a:b;
}
template<typename T>
__attribute__((always_inline)) void chkmax(T& a, const T& b) {
a=(a>b)?a:b;
}
//Constants.
#define MOD (ll(998244353))
#define MAX 300001
#define mag 320
const long double PI=3.14159265358979;
//Pairs and 3-pairs.
#define p1 first
#define p2 second.first
#define p3 second.second
#define fi first
#define se second
#define pii(element_type) pair<element_type,element_type>
#define piii(element_type) pair<element_type,pii(element_type)>
//Quick power of 2.
#define pow2(x) (ll(1)<<x)
//Short for-loops.
#define ff(i,__,___) for(int i=__;i<=___;i++)
#define rr(i,__,___) for(int i=__;i>=___;i--)
//Typedefs.
#define bi BigInt
typedef long long ll;
typedef long double ld;
typedef short sh;
// Binpow and stuff
ll BOW(ll a, ll x, ll p)
{
if (!x) return 1;
ll res=BOW(a,x/2,p);
res*=res;
res%=p;
if (x%2) res*=a;
return res%p;
}
ll INV(ll a, ll p)
{
return BOW(a,p-2,p);
}
//---------END-------//
#endif
// A list of preset merge functions.
//The segement tree itself.
struct seg
{
ll val[800001];
ll def=0;
ll (*merg)(ll,ll); // Merge function. It must be associative.
void reset(ll c, ll l, ll r)
{
if (l<r)
{
ll mid=(l+r)/2;
reset((c<<1),l,mid);
reset((c<<1)+1,mid+1,r);
val[c]=(val[(c<<1)]+val[(c<<1)+1]);
}
else val[c]=0;
}
void upd(ll c, ll l, ll r, ll x, ll t)
{
if ((l<=x)and(x<=r))
{
if (l==r) val[c]=t;
else
{
ll mid=(l+r)/2;
upd((c<<1),l,mid,x,t);
upd((c<<1)+1,mid+1,r,x,t);
val[c]=(val[(c<<1)]+val[(c<<1)+1]);
}
}
}
ll get(ll c, ll l, ll r, ll tl, ll tr)
{
if ((tl>r)or(tr<l)) return def;
if ((tl<=l)and(tr>=r)) return val[c];
else
{
ll mid=(l+r)/2;
ll a=get((c<<1),l,mid,tl,tr);
ll b=get((c<<1)+1,mid+1,r,tl,tr);
return (a+b);
}
}
};
seg st;
vector<int> gt[100001];
int n,m,i,j,k,t,t1,u,v,a,b;
ll res=0;
int ea[100001],eb[100001],crr[100001];
int cnt[100001];
int rn[100001],rp[100001];
int head[100001];
int par[100001];
vector<pii(int)> sta[100001];
map<int,int> lmao;
vector<pii(int)> req;
vector<int> cleanup;
void dfs(int x, int p)
{
cnt[x]=1;
for (auto g : gt[x]) if (g-p)
{
dfs(g,x);
cnt[x]+=cnt[g];
}
}
void build_path(int x)
{
if (rp[x]==1) head[rn[x]]=x;
sort(gt[x].begin(),gt[x].end(),[](int a, int b){
return (cnt[a]>cnt[b]);
});
if (gt[x].size())
{
rn[gt[x][0]]=t;
rp[gt[x][0]]=rp[x]+1;
build_path(gt[x][0]);
for (int i = 1; i<gt[x].size();i++)
{
t++;
rn[gt[x][i]]=t;
rp[gt[x][i]]=1;
build_path(gt[x][i]);
}
}
sta[rn[x]].push_back({crr[x],1});
}
int main()
{
fio;
cin>>n;
for (i=1;i<=n;i++)
{
cin>>crr[i];
lmao[crr[i]]=1;
}
t=0;
for (auto g : lmao)
{
t++;
lmao[g.fi]=t;
}
for (i=1;i<=n;i++)
{
crr[i]=lmao[crr[i]];
}
for (i=1;i<n;i++)
{
cin>>ea[i]>>eb[i];
par[eb[i]]=ea[i];
gt[ea[i]].push_back(eb[i]);
}
dfs(1,-1);
t=1;
rn[1]=1;
rp[1]=1;
build_path(1);
for (i=1;i<=n;i++)
{
// cout<<i<<' '<<rn[i]<<' '<<rp[i]<<endl;
}
st.reset(1,1,n);
for (t=1;t<n;t++)
{
res=0;
req.clear();
cleanup.clear();
u=ea[t];
while(u)
{
req.push_back({rn[u],rp[u]});
// cout<<u<<' '<<'{'<<rn[u]<<' '<<rp[u]<<'}'<<endl;
u=par[head[rn[u]]];
}
reverse(req.begin(),req.end());
for (auto g : req)
{
u=0;
while(u<g.se)
{
auto pp=sta[g.fi].back();
cleanup.push_back(pp.fi);
if (u+pp.se>g.se)
{
a=st.get(1,1,n,pp.fi+1,n);
res+=(ll)a*(g.se-u);
a=st.get(1,1,n,pp.fi,pp.fi);
st.upd(1,1,n,pp.fi,a+g.se-u);
sta[g.fi].back().se-=g.se-u;
u+=g.se-u;
}
else
{
a=st.get(1,1,n,pp.fi+1,n);
res+=(ll)a*(pp.se);
a=st.get(1,1,n,pp.fi,pp.fi);
st.upd(1,1,n,pp.fi,a+pp.se);
sta[g.fi].pop_back();
u+=pp.se;
}
}
sta[g.fi].push_back({crr[eb[t]],g.se});
}
for (auto g : cleanup) st.upd(1,1,n,g,0);
cout<<res<<endl;
// cout<<endl;
}
}
// Normie28;
