// This amazing code is by Eric Sunli Chen.
#include<bits/stdc++.h>
using namespace std;
template<typename T> bool get_int(T &x)
{
	char t=getchar();
	bool neg=false;
	x=0;
	for(; (t>'9'||t<'0')&&t!='-'&&t!=EOF; t=getchar());
	if(t=='-')neg=true,t=getchar();if(t==EOF)return false;
	for(; t<='9'&&t>='0'; t=getchar())x=x*10+t-'0';
	if(neg)x=-x;return true;
}
template<typename T> void print_int(T x)
{
	if(x<0)putchar('-'),x=-x;
	short a[20]= {},sz=0;
	while(x>0)a[sz++]=x%10,x/=10;
	if(sz==0)putchar('0');
	for(int i=sz-1; i>=0; i--)putchar('0'+a[i]);
}
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
#define get1(a) get_int(a)
#define get2(a,b) (get1(a)&&get1(b))
#define get3(a,b,c) (get1(a)&&get2(b,c))
#define printendl(a) print_int(a),puts("")
typedef long long LL;
typedef unsigned long long uLL;
typedef pair<int,int> pii;
const int inf=0x3f3f3f3f;
const LL Linf=1ll<<61;
const double pi=acos(-1.0);

const int maxn=200111;
const int maxm=200111;
struct max_flow
{
	struct edge{int to,cap;};
	int head[maxn],nxt[maxm<<1],iter[maxn],tot;
	edge e[maxm<<1];
	void clear()
	{
		memset(head,0,sizeof(head));
		tot=1;
	}
	max_flow(){clear();}
	void addedge(int u,int v,int cap)
	{
		nxt[++tot]=head[u];
		head[u]=tot;
		e[tot]=edge{v,cap};
		nxt[++tot]=head[v];
		head[v]=tot;
		e[tot]=edge{u,0};
	}
	
	int lvl[maxn],q[maxn];
	bool bfs(int s,int t)
	{
		memset(lvl,-1,sizeof(lvl));
		lvl[s]=0;int rr=0;q[rr++]=s;
		for(int fr=0;fr<rr;fr++)
		{
			int x=q[fr];if(x==t)return true;
			for(int i=head[x];i;i=nxt[i])if(e[i].cap&&lvl[e[i].to]==-1)
			{
				lvl[e[i].to]=lvl[x]+1;
				q[rr++]=e[i].to;
			}
		}
		return false;
	}
	int dfs(int x,int t,int f)
	{
		if(x==t||f==0)return f;
		int ret=0;
		for(int&i=iter[x];i;i=nxt[i])if(e[i].cap&&lvl[e[i].to]==lvl[x]+1)
		{
			int d=dfs(e[i].to,t,min(f,e[i].cap));
			e[i].cap-=d;e[i^1].cap+=d;
			f-=d;ret+=d;
			if(!f)break;
		}
		return ret;
	}
	int maxflow(int s,int t)
	{
		int flow=0;
		while(bfs(s,t))
		{
			memcpy(iter,head,sizeof(head));
			flow+=dfs(s,t,inf);
		}
		return flow;
	}
}thor;

int n,p[maxn],q[maxn],tot1,tot2,ip[maxn],iq[maxn];
int decomp(int*p,int*id)
{
	int ret=0;
	for(int i=1;i<=n;i++)if(!id[i])
	{
		int tmp=i;ret++;
		while(!id[tmp])
		{
			id[tmp]=ret;
			tmp=p[tmp];
		}
	}
	return ret;
}

int main()
{
	get1(n);
	for(int i=1;i<=n;i++)get1(p[i]),p[i]++;
	for(int i=1;i<=n;i++)get1(q[i]),q[i]++;
	
	tot1=decomp(p,ip);
	tot2=decomp(q,iq);
	
	int ans=n,S=tot1+tot2+1,T=S+1;
	for(int i=1;i<=n;i++)
	{
		if(p[i]==q[i])
		{
			if(p[i]==i)ans--;
			else
			{
				thor.addedge(ip[i],iq[i]+tot1,1);
				thor.addedge(iq[i]+tot1,ip[i],1);
			}
		}
		else
		{
			if(q[i]==i)thor.addedge(S,ip[i],1);
			else if(p[i]==i)thor.addedge(iq[i]+tot1,T,1);
			else thor.addedge(iq[i]+tot1,ip[i],1);
		}
	}
	ans-=thor.maxflow(S,T);
	printendl(ans);
	return 0;
}
