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#include<bits/stdc++.h>
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#define endl '\n'
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using namespace std;
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typedef long long ll;
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typedef pair<ll,ll> pll;
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vector<ll> v;
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vector<ll> tree;
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unordered_map<ll,pll> mp;
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ll count(ll x){
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    if(x==-1)return 0;
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    ll l=mp[x].first;
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    ll r=mp[x].second;
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    tree[x]=count(l)+count(r)+1;
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    return tree[x];
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}
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bool mirror(ll x,ll y){
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    if(x==-1&&y==-1)return true;
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    if(x==-1||y==-1)return false;
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    if(v[x]!=v[y])return false;
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    return mirror(mp[x].first,mp[y].second)&&mirror(mp[x].second,mp[y].first);
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}
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int main(){
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    ios::sync_with_stdio(false);cin.tie(0);
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    ll n;
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    cin>>n;
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    tree.resize(n+1);
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    v.resize(n+1);
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    for(ll i=1;i<=n;i++)cin>>v[i];
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    for(ll i=1;i<=n;i++){
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        cin>>mp[i].first>>mp[i].second;
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    }
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    ll ans=0;
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    count(1);
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    for(ll i=1;i<=n;i++){
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        if(mirror(i,i))ans=max(ans,tree[i]);
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    }
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    cout<<ans<<endl;
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    return 0;
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}