#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")

#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/rope>

using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
 
typedef string str;
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define F0R(i, a) for (int i = 0; i < (a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= (a); i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)
#define trav(a, x) for (auto& a : x)

#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound

#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rsz resize

const int MOD = 1000000007; // 998244353
const ll INF = 1e18;
const int MX = 200010;
const ld PI = 4*atan((ld)1);

template<class T> void ckmin(T &a, T b) { a = min(a, b); }
template<class T> void ckmax(T &a, T b) { a = max(a, b); }

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

namespace input {
	template<class T> void re(complex<T>& x);
	template<class T1, class T2> void re(pair<T1,T2>& p);
	template<class T> void re(vector<T>& a);
	template<class T, size_t SZ> void re(array<T,SZ>& a);

	template<class T> void re(T& x) { cin >> x; }
	void re(double& x) { string t; re(t); x = stod(t); }
	void re(ld& x) { string t; re(t); x = stold(t); }
	template<class T, class... Ts> void re(T& t, Ts&... ts) { 
		re(t); re(ts...); 
	}

	template<class T> void re(complex<T>& x) { T a,b; re(a,b); x = cd(a,b); }
	template<class T1, class T2> void re(pair<T1,T2>& p) { re(p.f,p.s); }
	template<class T> void re(vector<T>& a) { F0R(i,sz(a)) re(a[i]); }
	template<class T, size_t SZ> void re(array<T,SZ>& a) { F0R(i,SZ) re(a[i]); }
}

using namespace input;

namespace output {
	void pr(int x) { cout << x; }
	void pr(long x) { cout << x; }
	void pr(ll x) { cout << x; }
	void pr(unsigned x) { cout << x; }
	void pr(unsigned long x) { cout << x; }
	void pr(unsigned long long x) { cout << x; }
	void pr(float x) { cout << x; }
	void pr(double x) { cout << x; }
	void pr(ld x) { cout << x; }
	void pr(char x) { cout << x; }
	void pr(const char* x) { cout << x; }
	void pr(const string& x) { cout << x; }
	void pr(bool x) { pr(x ? "true" : "false"); }
	
	template<class T1, class T2> void pr(const pair<T1,T2>& x);
	template<class T> void pr(const T& x);
	
	template<class T, class... Ts> void pr(const T& t, const Ts&... ts) { 
		pr(t); pr(ts...); 
	}
	template<class T1, class T2> void pr(const pair<T1,T2>& x) { 
		pr("{",x.f,", ",x.s,"}"); 
	}
	template<class T> void pr(const T& x) { 
		pr("{"); // const iterator needed for vector<bool>
		bool fst = 1; for (const auto& a: x) pr(!fst?", ":"",a), fst = 0; 
		pr("}");
	}
	
	void ps() { pr("\n"); } // print w/ spaces
	template<class T, class... Ts> void ps(const T& t, const Ts&... ts) { 
		pr(t); if (sizeof...(ts)) pr(" "); ps(ts...); 
	}
	
	void pc() { pr("]\n"); } // debug w/ commas
	template<class T, class... Ts> void pc(const T& t, const Ts&... ts) { 
		pr(t); if (sizeof...(ts)) pr(", "); pc(ts...); 
	}
	#define dbg(x...) pr("[",#x,"] = ["), pc(x);
}

using namespace output;

namespace io {
	void setIn(string s) { freopen(s.c_str(),"r",stdin); }
	void setOut(string s) { freopen(s.c_str(),"w",stdout); }
	void setIO(string s = "") {
		cin.sync_with_stdio(0); cin.tie(0); // fast I/O
		cin.exceptions(cin.failbit); // ex. throws exception when you try to read letter into int
		if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
	}
}

using namespace io;

template<class T> T invGeneral(T a, T b) {
	a %= b; if (a == 0) return b == 1 ? 0 : -1;
	T x = invGeneral(b,a); 
	return x == -1 ? -1 : ((1-(ll)b*x)/a+b)%b;
}

template<class T> struct modular {
	T val; 
	explicit operator T() const { return val; }
	modular() { val = 0; }
	modular(const ll& v) { 
		val = (-MOD <= v && v <= MOD) ? v : v % MOD;
		if (val < 0) val += MOD;
	}
	
	// friend ostream& operator<<(ostream& os, const modular& a) { return os << a.val; }
	friend void pr(const modular& a) { pr(a.val); }
	friend void re(modular& a) { ll x; re(x); a = modular(x); }
   
	friend bool operator==(const modular& a, const modular& b) { return a.val == b.val; }
	friend bool operator!=(const modular& a, const modular& b) { return !(a == b); }
	friend bool operator<(const modular& a, const modular& b) { return a.val < b.val; }

	modular operator-() const { return modular(-val); }
	modular& operator+=(const modular& m) { if ((val += m.val) >= MOD) val -= MOD; return *this; }
	modular& operator-=(const modular& m) { if ((val -= m.val) < 0) val += MOD; return *this; }
	modular& operator*=(const modular& m) { val = (ll)val*m.val%MOD; return *this; }
	friend modular pow(modular a, ll p) {
		modular ans = 1; for (; p; p /= 2, a *= a) if (p&1) ans *= a;
		return ans;
	}
	friend modular inv(const modular& a) { 
		auto i = invGeneral(a.val,MOD); assert(i != -1);
		return i;
	} // equivalent to return exp(b,MOD-2) if MOD is prime
	modular& operator/=(const modular& m) { return (*this) *= inv(m); }
	
	friend modular operator+(modular a, const modular& b) { return a += b; }
	friend modular operator-(modular a, const modular& b) { return a -= b; }
	friend modular operator*(modular a, const modular& b) { return a *= b; }
	
	friend modular operator/(modular a, const modular& b) { return a /= b; }
};

typedef modular<int> mi;
typedef pair<mi,mi> pmi;
typedef vector<mi> vmi;
typedef vector<pmi> vpmi;

typedef ll F; // flow type
struct Edge { int v, rev; F f, c; };

template<int SZ> struct Dinic {
    vector<Edge> adj[SZ];
    vector<Edge>::iterator cur[SZ];
    void addEdge(int u, int v, F cap, F rcap = 0) {
        assert(min(cap,rcap) >= 0); // don't try smth dumb
        Edge a{v, sz(adj[v]), 0, cap}, b{u, sz(adj[u]), 0, rcap};
        adj[u].pb(a), adj[v].pb(b);
    }

    int N, st, en;
    int level[SZ];
    bool bfs() { // level = shortest distance from source
        // after computing flow, edges {u,v} such that level[u] \neq -1, level[v] = -1 are part of min cut
        F0R(i,N) level[i] = -1, cur[i] = begin(adj[i]);
        queue<int> q; level[st] = 0; q.push(st);
        while (sz(q)) {
            int u = q.front(); q.pop();
            trav(e,adj[u]) if (level[e.v] < 0 && e.f < e.c) {
                level[e.v] = level[u]+1; q.push(e.v);
            }
        }
        return level[en] >= 0;
    }

    F sendFlow(int s, F flow) {
        if (s == en) return flow;
        for (; cur[s] != end(adj[s]); cur[s]++) {
            Edge& e = *cur[s];
            if (level[e.v] != level[s]+1 || e.f == e.c) continue;
            auto f = sendFlow(e.v, min(flow, e.c-e.f));
            if (f) { // saturated at least one edge
                e.f += f; adj[e.v][e.rev].f -= f;
                return f;
            }
        }
        return 0;
    }
    F maxFlow(int _N, int _st, int _en) {
        N = _N; st = _st, en = _en; if (st == en) return -1;
        F tot = 0;
        while (bfs()) while (auto flow = sendFlow(st, LLONG_MAX)) tot += flow;
        return tot;
    }
};

Dinic<MX> D;

int N, vis[MX], A[MX], B[MX], cnt[MX];
set<int> adj[MX];
map<pi,int> bad;

vector<vi> gen(vi v) {
	F0R(i,N) vis[i] = 0;
	F0R(i,N) if (!vis[i]) {
		int x = i;
		while (!vis[x]) {
			vis[x] = i+1;
			x = v[x];
		}
		if (vis[x] != i+1) continue;
		while (vis[x] == i+1) {
			vis[x] = N+i+1;
			x = v[x];
		}
	}
	vector<vi> res;
	F0R(i,N) if (vis[i] != MOD) {
		if (vis[i] <= N) res.pb({i});
		else {
			int x = i; vi tmp;
			while (vis[x] != MOD) {
				tmp.pb(x); vis[x] = MOD;
				x = v[x];
			}
			res.pb(tmp);
		}
	}
	/*F0R(i,N) pr(vis[i],' ');
	ps();*/
	return res;
}

/*void addEdge(int x, int y) {
	ps("HUH",x,y);
	adj[x].insert(y), adj[y].insert(x);
}*/

int main() {
	setIO(); re(N); 
	vi P(N), Q(N); re(P,Q);
	auto a = gen(P), b = gen(Q);
	F0R(i,sz(a)) trav(t,a[i]) A[t] = i;
	F0R(i,sz(b)) trav(t,b[i]) B[t] = i;
	F0R(i,N) {
		if (sz(a[A[i]]) == 1) {
			if (sz(b[B[i]]) == 1) continue;
			cnt[sz(a)+1+B[i]] ++;
		} else {
			if (sz(b[B[i]]) == 1) cnt[1+A[i]] ++;
			else {
				cnt[1+A[i]] ++, cnt[1+sz(a)+B[i]] ++;
				if (P[i] == Q[i]) bad[{1+A[i],1+sz(a)+B[i]}] += 2;
				else bad[{1+A[i],1+sz(a)+B[i]}] += 1;
			}
		}
	}
	F0R(i,sz(a)) if (cnt[1+i]) D.addEdge(0,1+i,cnt[1+i]);
	F0R(i,sz(b)) if (cnt[sz(a)+1+i]) D.addEdge(sz(a)+1+i,sz(a)+sz(b)+1,cnt[sz(a)+1+i]);
	trav(t,bad) D.addEdge(t.f.f,t.f.s,t.s);
	ll ans = 0;
	FOR(i,1,sz(a)+sz(b)+1) ans += cnt[i];
	// ps("HUH",ans);
	ps(ans-D.maxFlow(sz(a)+sz(b)+2,0,sz(a)+sz(b)+1));
}

/* stuff you should look for
	* int overflow, array bounds
	* special cases (n=1?), set tle
	* do smth instead of nothing and stay organized
*/


Measured memory_bytes: 37292