#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<vector>
#include<queue>
#include<map>
#include<bitset>
#include<set>
#define N (400010)
#define P ()
#define M ()
#define inf (0x7f7f7f7f)
#define rg register int
#define Label puts("NAIVE")
#define spa print(' ')
#define ent print('\n')
#define rand() (((rand())<<(15))^(rand()))
#define file(s) freopen(s".in","r",stdin),freopen(s".out","w",stdout)
typedef long double ld;
typedef long long LL;
typedef unsigned long long ull;
using namespace std;
namespace fastIO1{
	inline char read(){
		static const int IN_LEN=1000000;
		static char buf[IN_LEN],*s,*t;
		return (s==t?t=(s=buf)+fread(buf,1,IN_LEN,stdin),(s==t?-1:*s++):*s++);
	}
	template<class T>
	inline void read(T &x){
		static bool iosig;
		static char c;
		for(iosig=false,c=read();!isdigit(c);c=read()){
			if(c=='-')iosig=true;
			if(c==-1)return;
		}
		for(x=0;isdigit(c);c=read())x=((x+(x<<2))<<1)+(c^'0');
		if(iosig)x=-x;
	}
	inline char readc(char &c){
		for(c=read();!isalpha(c)&&!isdigit(c);c=read())
		if(c==-1)return 0;
	}
	const int OUT_LEN = 10000000;
	char obuf[OUT_LEN],*ooh=obuf;
	inline void print(char c) {
		if(ooh==obuf+OUT_LEN)fwrite(obuf,1,OUT_LEN,stdout),ooh=obuf;
		*ooh++=c;
	}
	template<class T>
	inline void print(T x){
		static int buf[30],cnt;
		if(x==0)print('0');
		else{
			if(x<0)print('-'),x=-x;
			for(cnt=0;x;x/=10)buf[++cnt]=x%10+48;
			while(cnt)print((char)buf[cnt--]);
		}
	}
	inline void flush(){fwrite(obuf,1,ooh-obuf,stdout);}
}
namespace fastIO2{
	template<class T>
	inline void read(T &x){
		static bool iosig;
		static char c;
		for(iosig=false,c=getchar();!isdigit(c);c=getchar()){
			if(c=='-')iosig=true;
			if(c==-1)return;
		}
		for(x=0;isdigit(c);c=getchar())x=((x+(x<<2))<<1)+(c^'0');
		if(iosig)x=-x;
	}
}
using namespace fastIO1;
queue<int> Q;
int cur[N],fi[N],ne[N],to[N],c[N],dis[N];
int n,m,S,T,V,E,ans,a[N],b[N],p1[N],p2[N];
void add(int x,int y,int z){
	ne[++E]=fi[x],fi[x]=E,to[E]=y,c[E]=z;
	ne[++E]=fi[y],fi[y]=E,to[E]=x,c[E]=0;
}
bool bfs(int S,int T){
	while(!Q.empty())Q.pop(); Q.push(S);
	for(int i=1;i<=V;i++)dis[i]=inf,cur[i]=fi[i]; dis[S]=0;
	while(!Q.empty()){
		int u=Q.front();Q.pop();
		for(int i=fi[u];i;i=ne[i])
		if(c[i]&&dis[to[i]]==inf){
			int v=to[i];
			dis[v]=dis[u]+1;
			if(v==T)return 1; Q.push(v);
		}
	}
	return dis[T]<=V;
}
int dfs(int u,int T,int flow){
	if(u==T)return flow;
	int usd=0;
	for(int i=cur[u];i;i=cur[u]=ne[i])
	if(c[i]&&dis[to[i]]==dis[u]+1){
		int fl=dfs(to[i],T,min(flow-usd,c[i]));
		if(!fl)continue;c[i]-=fl,c[i^1]+=fl,usd+=fl;
		if(usd>=flow)return usd;
	}
	return usd;
}
int dinic(int S,int T){
	int ans=0;
	while(bfs(S,T))ans+=dfs(S,T,inf);
	return ans;	
}
int main(){
	read(n),E=1;
	for(int i=1;i<=n;i++)read(a[i]),a[i]++;
	for(int i=1;i<=n;i++)read(b[i]),b[i]++;
	for(int i=1;i<=n;i++)
	if(!p1[i]){p1[i]=++S;for(int j=a[i];j!=i;j=a[j])p1[j]=S;}
	for(int i=1;i<=n;i++)
	if(!p2[i]){p2[i]=++S;for(int j=b[i];j!=i;j=b[j])p2[j]=S;}
	S++,V=T=S+1,ans=n;
	for(int i=1;i<=n;i++){
		if(a[i]==b[i]){
			if(a[i]==i)ans--;
			else add(p1[i],p2[i],1),add(p2[i],p1[i],1);
		}
		else{
			if(a[i]==i)add(p2[i],T,1);
			else if(b[i]==i)add(S,p1[i],1);
			else add(p2[i],p1[i],1);
		}
	}
//	puts("FAQ");
	cout<<ans-dinic(S,T);
}

Measured memory_bytes: 20480