#include<bits/stdc++.h>
#define pb push_back
#define fi first
#define se second
#define mp make_pair
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef long double ld;
template <typename T> bool chkmin(T &x,T y){return x>y?x=y,1:0;}
template <typename T> bool chkmax(T &x,T y){return x<y?x=y,1:0;}
int readint(){
int x=0,f=1; char ch=getchar();
while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
return x*f;
}
int n,tsz,dfn[400005],dfo[400005],fenw[400005];
vector<int> ch[400005],ord;
ll ans;
void change(int p,int x){
for(;p<400005;p+=p&-p) fenw[p]+=x;
}
int query(int p){
int ret=0;
for(;p;p-=p&-p) ret+=fenw[p];
return ret;
}
int make(){
int x=readint();
if(x){
dfn[x]=ord.size();
dfo[x]=ord.size();
ord.pb(x);
return x;
}
int nd=++tsz;
ch[nd].pb(make());
ch[nd].pb(make());
dfn[nd]=dfn[ch[nd][0]];
dfo[nd]=dfo[ch[nd][1]];
return nd;
}
void dfs(int x,bool ok){
if(x<=n){
if(ok) change(x,+1);
return;
}
int szl=dfo[ch[x][0]]-dfn[ch[x][0]];
int szr=dfo[ch[x][1]]-dfn[ch[x][1]];
if(szl>szr) swap(szl,szr),swap(ch[x][0],ch[x][1]);
dfs(ch[x][0],0);
dfs(ch[x][1],1);
ll inv=0;
for(int i=dfn[ch[x][0]];i<=dfo[ch[x][0]];i++){
inv+=query(ord[i]-1);
}
inv=min(inv,(szl+1)*1ll*(szr+1)-inv);
ans+=inv;
if(ok) for(int i=dfn[ch[x][0]];i<=dfo[ch[x][0]];i++) change(ord[i],1);
else for(int i=dfn[ch[x][1]];i<=dfo[ch[x][1]];i++) change(ord[i],-1);
}
int main(){
n=readint();
tsz=n;
int rt=make();
dfs(rt,0);
printf("%lld",ans);
return 0;
}
