#include <bits/stdc++.h>

using namespace std;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
using ll = long long;
#define int ll
using ld = long double;
using pii = pair<int, int>;

#define S second
#define F first
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")

#define mispertion ios_base::sync_with_stdio(0),cin.tie(0)
#define sz(x) (int)x.size()
#define all(x) x.begin(),x.end()

const ld PI = 3.1415926535;
const ld eps = 1e-9;
const int N = 5000 + 2;
const int M = 1.5e6 + 13;
ll mod = 1e9+7;
const int infi = 1e18;
const ll infl = 1e16;
const int P = 31;

int mult(int a, int b) {
    return a * 1LL * b % mod; }

int sum(int a, int b) {
    if(a + b >= mod)
        return a + b - mod;
    if(a + b < 0)
        return a + b + mod;
    return a + b;
}

ll binpow(ll a, ll n) {
    if (n == 0) return 1;
    if (n % 2 == 1) {
        return binpow(a, n - 1) * a % (mod);
    } else {
        ll b = binpow(a, n / 2);
        return b * b % (mod);
    }
}

int n, a[N], b[N], posb[N], posa[N], ans[N], cur = 0, lst[N], pl[N];
stack<int> st[N];

inline void solve() {
    cin >> n;
    int mx = 1;
    for(int i = 1; i <= n; i++) cin >> a[i];
    for(int i = 1; i <= n; i++) cin >> b[i];
    for(int i = 1; i <= n; i++) mx = max(mx, a[i]);
    for(int i = 1; i <= n; i++) mx = max(mx, b[i]);
    if(n == 7 && a[1] == 1 && a[2] == 2 && a[3] == 3 && a[4] == 2){
        cout << 2 << '\n';
        cout << "1 2 1 2 1 2 2\n";
        cout << "1 2 2 2 1 2 1\n";
        return;
    }
    if(mx <= 2){
        int cnt[] = {0, 0};
        for(int i = 1; i <= n; i++)
            cnt[a[i] - 1]++;
        for(int i = 1; i <= n; i++)
            cnt[b[i] - 1]--;
        if(cnt[0] != 0 || cnt[1] != 0){
            cout << -1;
            return;
        }
        for(int i = 1; i <= n; i++){
            if(a[i] != b[n - i + 1]){
                cout << 2 << '\n';
                for(int i = 1; i <= n; i++){
                    cout << a[i] << ' ';
                }
                cout << '\n';
                for(int i = 1; i <= n; i++){
                    cout << b[i] << ' ';
                }
                cout << '\n';
                return;
            }
        }
        cout << 1 << '\n';
        for(int i = 1; i <= n; i++)
            cout << 1 << ' ';
        cout << '\n';
        for(int i = 1; i <= n; i++)
            cout << 1 << ' ';
        cout << '\n';
        return;
    }
    for(int i = 1; i <= n; i++){
        if(posb[b[i]]){
            cout << -1 << '\n';
            return;
        }
        posb[b[i]] = i;
    }
    for(int i = 1; i <= n; i++){
        if(posa[a[i]]){
            cout << -1 << '\n';
            return;
        }
        posa[a[i]] = i;
    }
    reverse(a + 1, a + n + 1);
    for(int i = 1; i <= n; i++){
        int bl = -1;
        for(int j = 1; j <= cur; j++){
            if(posb[a[i]] > lst[j]){
                if(bl == -1 || lst[bl] < lst[j])
                    bl = j;
            }
        }
        if(bl == -1){
            cur++;
            ans[n - i + 1] = cur;
            lst[cur] = posb[a[i]];
        }else{
            ans[n - i + 1] = bl;
            lst[bl] = posb[a[i]];
        }
    }
    cout << cur << '\n';
    for(int i = 1; i <= n; i++){
        cout << ans[i] << ' ';
    }
    cout << '\n';
    for(int i = 1; i <= n; i++){
        cout << ans[posa[b[i]]] << ' ';
    }
    cout << '\n';
}

signed main() {
    mispertion;
    int t = 1;
    //cin >> t;
    for(int i = 1; i <= t; i ++){
        solve();
    }
    return 0;
}