#include<bits/stdc++.h>
#define pb emplace_back
#define fi first
#define se second
#define mp make_pair
using namespace std;
typedef long long ll;
const int maxn=2e5+10;
const int maxlog=20;
void cmax(int &x,int y){ x=x>y?x:y; }
void cmin(int &x,int y){ x=x<y?x:y; }
ll val[maxn],ans=0; int n,vis[maxn];
int sz[maxn],col[maxn],S,C,cur;
ll F(ll x){ return 143*x*x*x+(x>>1)+(x*x^343243); }
ll random(){ return F(rand())+(rand()<<3)+(rand()>>1); }
struct Tree{
	int dfn[maxn],pa[maxlog][maxn];
	int lg[maxn],dep[maxn],tot=0; ll s[maxn];
	vector<int> G[maxn];
	void dfs(int u,int fa){
		pa[0][dfn[u]=++tot]=fa; dep[u]=dep[fa]+1;
		for(auto v:G[u]) 
			if(v!=fa) dfs(v,u);
	}
	int cmp(int x,int y){ return dfn[x]<dfn[y]?x:y; }
	int lca(int u,int v){
		if(u==v) return u;
		u=dfn[u]; v=dfn[v];
		if(u>v) swap(u,v);
		u++; int k=lg[v-u+1];
		return cmp(pa[k][u],pa[k][v-(1<<k)+1]);
	}
	void init(){
		dfs(1,0); lg[1]=0;
		for(int i=2;i<=n;i++) lg[i]=lg[i>>1]+1;
		for(int k=1;(1<<k)<=n;k++)
			for(int i=1;i+(1<<k)-1<=n;i++)
				pa[k][i]=cmp(pa[k-1][i],pa[k-1][i+(1<<k-1)]);
	}
	bool chk(int u,int v,int w){
		cur=v;
		if(dep[v]>dep[u]) swap(v,u);
		if(dep[v]>dep[w]) swap(v,w);
		if(dep[u]<dep[w]) swap(u,w); // u最深，v最浅
		int luw=lca(u,w),luv=lca(u,v),lvw=lca(v,w);
		//case 1: u-w-v
		if(luw==w&&lvw==v) return (w==cur);
		//case 2: u-v-w
		if(dep[v]<dep[luw]||(luv!=v&&lvw!=v)) return 0;
		return (v==cur);	
	}
	void calc(int u,int fa,int Col){
		s[u]=s[fa]^val[u]; if(!Col) Col=u; col[u]=Col;
		for(auto v:G[u])
			if(v!=fa&&!vis[v]) calc(v,u,Col);
	}
	ll get(int u,int v){ if(!u) return 0; return s[u]^s[v]; }
}t1,t2;
vector<int> G[maxn],E[maxn];
map<ll,int> sx,sy,s;
vector<ll> vx,vy,vec;
int calc(int u,int fa){
	sz[u]=1; int mx=0;
	for(auto v:G[u])
		if(v!=fa&&!vis[v]) sz[u]+=calc(v,u),cmax(mx,sz[v]);
	cmax(mx,S-sz[u]); if(mx<=S/2) C=u;
	return sz[u];
}
int find(int u){ S=calc(u,0); S=calc(u,0); return C; }
void dfs(int u,int fa,int p1,int p2){
	if(!p1) p1=u;
	else if(t2.chk(u,p1,C)) p1=u;
	else if(col[u]==col[p1]) return ;
	else if(!p2) p2=u;
	else if(t2.chk(u,p2,C)) p2=u; 
	else return ;
	ll Sx=t1.get(u,C);
	ll S=t2.get(p1,C)^t2.get(p2,C);// path(p1,p2)\{u}
	vx.pb(Sx^S); vy.pb(t1.get(u,C));
	vec.pb(Sx^t2.get(p1,C));
	if(p2) vec.pb(Sx^t2.get(p2,C)); 
	for(auto v:G[u]){
		if(v==fa||vis[v]) continue;
		dfs(v,u,p1,p2);
	}
}
void solve(int u){
//	cout<<"U"<<u<<endl;
	t1.calc(u,0,0); t2.calc(u,0,0);//计算 s 数组 
	vis[u]=1; sx.clear(); sy.clear(); s.clear();
	sy[0]=1;
	for(auto v:G[u]){
		if(vis[v]) continue;
		vec.clear(); vx.clear(); vy.clear();
		dfs(v,u,0,0);
		for(auto z:vx)
			if(sy.find(z)!=sy.end()) ans+=sy[z];
		for(auto z:vy)
			if(sx.find(z)!=sx.end()) ans+=sx[z];
		for(auto z:vec) 
			if(s.find(z)!=s.end()) ans+=s[z];
		for(auto z:vx) sx[z]++;
		for(auto z:vy) sy[z]++;
		for(auto z:vec) s[z]++;
	}
	for(auto v:G[u])
		if(!vis[v]) solve(find(v));
}
int main(){
	ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	srand((unsigned)time(0));
	cin>>n; int F;
	for(int i=2;i<=n;i++) cin>>F,G[F].pb(i);
	for(int i=2;i<=n;i++) cin>>F,E[F].pb(i);
	for(int i=1;i<=n;i++) val[i]=random();
	for(int i=1;i<=n;i++) t1.G[i]=G[i],t2.G[i]=E[i];
	t1.init(); t2.init();
	solve(find(1)); cout<<ans+n; 
	return 0;
}

answer.code:15:4: error: ambiguating new declaration of ‘ll random()’
   15 | ll random(){ return F(rand())+(rand()<<3)+(rand()>>1); }
      |    ^~~~~~
In file included from /usr/include/c++/14/cstdlib:79,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:42,
                 from answer.code:1:
/usr/include/stdlib.h:521:17: note: old declaration ‘long int random()’
  521 | extern long int random (void) __THROW;
      |                 ^~~~~~