#pragma GCC optimize("Ofast,unroll-loops,no-stack-protector,fast-math")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
//#pragma comment(linker, "/stack:200000000")
 
#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
typedef double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<ld,ld> pdd;
 
#define X first
#define Y second
 
//#include <boost/unordered_map.hpp>
//using namespace boost;
 
/*
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> rbtree;
rbtree T;
*/
 
using i32 = int;
using i64 = long long;
using u8 = unsigned char;
using u32 = unsigned;
using u64 = unsigned long long;
using f64 = double;
using f80 = long double;
//using i128 = __int128_t;
//using u128 = __uint128_t;
//using i128 = i64;
//using u128 = u64;
 
ll power(ll a, ll b, ll p)
{
	if (!b) return 1;
	ll t = power(a, b/2, p);
	t = t*t%p;
	if (b&1) t = t*a%p;
	return t;
}
 
ll exgcd(ll a, ll b, ll &x, ll &y)
{
	if (b == 0)
	{
		x = 1;
		y = 0;
		return a;
	}
	ll px, py;
	ll d = exgcd(b, a%b, px, py);
	x = py;
	y = px-a/b*py;
	return d;
}
 
template<class T>
inline void freshmin(T &a, const T &b)
{
	if (a > b) a = b;
}
 
template<class T>
inline void freshmax(T &a, const T &b)
{
	if (a < b) a = b;
}
 
//#define getchar getchar_unlocked
//#define putchar putchar_unlocked

#define FWRITE

namespace io
{

#ifndef FWRITE
#include <unistd.h>
#endif
const int BUFSIZE = 1<<20;

int isize, osize;
char ibuf[BUFSIZE+10], obuf[BUFSIZE+10];
char *is, *it, *os = obuf, *ot = obuf+BUFSIZE;

char getchar()
{
	if (is == it)
	{
		is = ibuf;
		#ifdef FWRITE
		it = ibuf+fread(ibuf, 1, BUFSIZE, stdin);
		#else
		it = ibuf+read(STDIN_FILENO, ibuf, BUFSIZE);
		#endif
		if (is == it) return EOF;
	}
	return *is ++;
}

char getalpha()
{
	char c = getchar();
	while (!isalpha(c)) c = getchar();
	return c;
}

void putchar(char c)
{
	*os ++ = c;
	if (os == ot)
	{
		#ifdef FWRITE
		fwrite(obuf, 1, BUFSIZE, stdout);
		#else
		write(STDOUT_FILENO, obuf, BUFSIZE);
		#endif
		os = obuf;
	}
}

int inp() {
	int x = 0, f = 0; char ch;
	for(ch = getchar(); !isdigit(ch); ch = getchar())
		if(ch == '-') f = 1;
	for(; isdigit(ch); x = x * 10 + ch - '0', ch = getchar());
	return f ? -x : x;
}

ll inp_ll() {
	ll x = 0; int f = 0; char ch;
	for(ch = getchar(); !isdigit(ch); ch = getchar())
		if(ch == '-') f = 1;
	for(; isdigit(ch); x = x * 10 + ch - '0', ch = getchar());
	return f ? -x : x;
}

template<class T>
bool read(T &x)
{
	x = 0;
	char ch = getchar();
	if (ch == EOF) return 0;
	for(; !isdigit(ch); )
	{
		ch = getchar();
		if (ch == EOF) return 0;
	}
	for(; isdigit(ch); x = x * 10 + ch - '0', ch = getchar());
	return 1;
}

template<class T>
void write(T x)
{
	static char s[22];
	static char *it = s+20;
	static char *end = s+20;
	
	if (x < 0)
	{
		putchar('-');
		x = -x;
	}
	
	do
	{
		*-- it = x%10+'0';
		x /= 10;
	}
	while (x);
	/*
	if (!x)
		*-- it = '0';
	while (x)
	{
		*-- it = x%10+'0';
		x /= 10;
	}
	*/
	for (; it < end; ++ it)
		putchar(*it);
}

template<>
void write(const char *s)
{
	for (; *s; ++ s) putchar(*s);
}

template<>
void write(char c)
{
	putchar(c);
}

template<class T, class V>
void write(T x, V y)
{
	write(x);
	write(y);
}

template<class T>
void writeln(T x)
{
	write(x);
	putchar('\n');
}

struct ender
{
	~ender()
	{
		if (os != obuf)
			#ifdef FWRITE
			fwrite(obuf, 1, os-obuf, stdout);
			#else
			write(STDOUT_FILENO, obuf, os-obuf);
			#endif
	}
}__ender;

}

template<class T>
void print(const T &a)
{
	for (auto x : a) printf("%d ", x); puts("");
}

const int MAXN = 100010;
const int MAXM = 1000010;
const int INF = 2000000000;
//const i64 INF = 2000000000000000000LL;
const int MOD = 998244353;
const int INV2 = (MOD+1)/2;
//const int INV6 = power(6, MOD-2, MOD);

using namespace io;

//mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());

const int N = 110000;

namespace dinic {

	using F = int;
	const F INF = 1e9+1e8;

	const int N = 220000;
	const int M = 1100000;

	int fst[N], nxt[M], to[M];
	F cap[M];
	int dis[N], q[N], ptr[N];
	int V, E;

	void init(int n) {
		memset(fst, -1, sizeof fst);
		V = n;
		E = 0;
	}
	
	inline void add_edge(int u, int v, F c, F d = 0) {
		to[E] = v, cap[E] = c, nxt[E] = fst[u], fst[u] = E++;
		to[E] = u, cap[E] = d, nxt[E] = fst[v], fst[v] = E++;
	}
	inline bool bfs(int S, int T, int n) {
		memset(dis, -1, sizeof(int) * n);
		int h = 0, t = 0;
		dis[S] = 0, q[t++] = S;
		while (h < t) {
			int u = q[h++];
			for (int e = fst[u]; ~e; e = nxt[e]) if (cap[e] > 0 && dis[to[e]] == -1) {
				dis[to[e]] = dis[u] + 1, q[t++] = to[e];
				if (to[e] == T) return 1;
			}
		}
		return (dis[T] != -1);
	}
	F dfs(int u, int T, F f) {
		if (u == T) return f;
		for (int &e = ptr[u]; ~e; e = nxt[e]) if (cap[e] > 0 && dis[to[e]] > dis[u]) {
			F ret = dfs(to[e], T, min(f, cap[e]));
			if (ret > 0) {
				cap[e] -= ret, cap[e ^ 1] += ret;
				return ret;
			}
		}
		return 0;
	}
	F max_flow(int S, int T, int n = V) {
		F ret = 0;
		while (bfs(S, T, n)) {
			memcpy(ptr, fst, sizeof(int) * n);
			for (F cur; (cur = dfs(S, T, INF)) > 0; ret += cur);
		}
		return ret;
	}
}

int n;
int p[MAXN], q[MAXN];

int pc[MAXN], qc[MAXN], pf[MAXN], qf[MAXN];

int F[MAXN];

int father(int x)
{
	return F[x] == x ? x : F[x] = father(F[x]);
}

void solve()
{
	n = inp();
	for (int i = 1; i <= n; ++ i)
	{
		p[i] = inp()+1;
	}
	for (int i = 1; i <= n; ++ i)
	{
		q[i] = inp()+1;
	}
	
	int S = 2*n+1, T = 2*n+2;
	dinic::init(2*n+5);
	
	for (int i = 1; i <= n; ++ i) F[i] = i;
	for (int i = 1; i <= n; ++ i) F[father(i)] = father(p[i]);
	for (int i = 1; i <= n; ++ i) pf[i] = father(i);
	
	for (int i = 1; i <= n; ++ i) F[i] = i;
	for (int i = 1; i <= n; ++ i) F[father(i)] = father(q[i]);
	for (int i = 1; i <= n; ++ i) qf[i] = father(i);
	
	int ans = 0;
	for (int i = 1; i <= n; ++ i)
	{
		if (p[i] == i && q[i] == i)
			++ ans;
		else if (p[i] == i)
			qc[qf[i]] ++;
		else if (q[i] == i)
			pc[pf[i]] ++;
		else if (p[i] != q[i])
			dinic::add_edge(qf[i]+n, pf[i], 1);
		else
		{
			dinic::add_edge(pf[i], qf[i]+n, 1, 1);
		}
	}
	for (int i = 1; i <= n; ++ i)
	{
		if (pc[i]) dinic::add_edge(S, i, pc[i]);
		if (qc[i]) dinic::add_edge(i+n, T, qc[i]);
	}
	
	ans += dinic::max_flow(S, T);
	
	cout << n-ans << endl;
}

int main()
{
	
	//for (int T = inp(); T --; )
		solve();
	
	return 0;
}


Measured memory_bytes: 19584