/*
    author:  Maksim1744
    created: 18.01.2020 15:26:08
*/

#include <bits/stdc++.h>

using namespace std;

#define ll   long long
#define ld   long double

#define mp   make_pair
#define pb   push_back
#define eb   emplace_back

#define sum(a)     ( accumulate ((a).begin(), (a).end(), 0ll))
#define mine(a)    (*min_element((a).begin(), (a).end()))
#define maxe(a)    (*max_element((a).begin(), (a).end()))
#define mini(a)    ( min_element((a).begin(), (a).end()) - (a).begin())
#define maxi(a)    ( max_element((a).begin(), (a).end()) - (a).begin())
#define lowb(a, x) ( lower_bound((a).begin(), (a).end(), (x)) - (a).begin())
#define uppb(a, x) ( upper_bound((a).begin(), (a).end(), (x)) - (a).begin())

template<typename T>             vector<T>& operator--            (vector<T>& v){for (auto& i : v) --i;            return  v;}
template<typename T>             vector<T>& operator++            (vector<T>& v){for (auto& i : v) ++i;            return  v;}
template<typename T>             istream& operator>>(istream& is,  vector<T>& v){for (auto& i : v) is >> i;        return is;}
template<typename T>             ostream& operator<<(ostream& os,  vector<T>& v){for (auto& i : v) os << i << ' '; return os;}
template<typename T, typename U> istream& operator>>(istream& is, pair<T, U>& p){is >> p.first >> p.second;        return is;}
template<typename T, typename U> ostream& operator<<(ostream& os, pair<T, U>& p){os << p.first << ' ' << p.second; return os;}
template<typename T, typename U> pair<T,U> operator-(pair<T,U> a, pair<T,U> b){return mp(a.first-b.first, a.second-b.second);}
template<typename T, typename U> pair<T,U> operator+(pair<T,U> a, pair<T,U> b){return mp(a.first+b.first, a.second+b.second);}
template<typename T, typename U> void umin(T& a, U b){if (a > b) a = b;}
template<typename T, typename U> void umax(T& a, U b){if (a < b) a = b;}

#ifdef HOME
#define TAG_LENGTH       25
#define LR_LEFT          left
#define LR_RIGHT         right
#define LR_VALUE         value
#define LR_SECOND_VALUE  mn
#include "C:/C++ libs/print.cpp"
#else
#define showl            42;
#define shows            42;
#define show(...)        42;
#define showm(...)       42;
#define showt(...)       42;
#define printTree(...)   42;
#define printGraph(...)  42;
#define printLRTree(...) 42;
#define printMatrix(...) 42;
#define printWGraph(...) 42;
#define debug     if (false)
#endif

int main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);

    int n;
    cin >> n;
    vector<int> a(n);
    vector<int> b(n);
    cin >> a >> b;
    int ans = 1e9;
    for (int i = 0; i < (1 << n); ++i) {
        vector<int> v(n, 0);
        for (int j = 0; j < n; ++j) {
            if ((i >> j) & 1) {
                v[j] = 1;
            }
        }
        vector<int> res;
        for (int j = 0; j < n; ++j) {
            if (v[j]) res.eb(b[j]);
            else res.eb(a[j]);
        }
        auto has = res;
        sort(res.begin(), res.end());
        // vector<int> c(2, 0);
        // int sm = 0;
        // for (int ii = 0; ii < n; ++ii) {
        //     int from = -1;
        //     for (int j = 0; j < n; ++j) {
        //         if (has[j].first != -1) {
        //             from = j;
        //             break;
        //         }
        //     }
        //     if (from == -1) break;
        //     int to = -1;
        //     for (int j = 0; j < n; ++j) {
        //         if ((from + has[from].second) % 2 == j % 2 && has[from].first == res[j].first) {
        //             to = j;
        //             break;
        //         }
        //     }
        //     if (to == -1) break;
        //     if (from < to) {
        //         for (int j = from; j < to; ++j) {
        //             swap(has[j], has[j + 1]);
        //             has[j].second ^= 1;
        //             has[j + 1].second ^= 1;
        //             ++sm;
        //         }
        //     } else {
        //         for (int j = from - 1; j >= to; --j) {
        //             swap(has[j], has[j + 1]);
        //             has[j].second ^= 1;
        //             has[j + 1].second ^= 1;
        //             ++sm;
        //         }
        //     }
        //     has[to].first = -1;
        //     res[to].first = -1;
        // }
        bool ok = true;
        vector<int> to(n, -1);
        for (int i = 0; i < n; ++i) {
            for (int j = 0; j < n; ++j) {
                if ((i + v[i]) % 2 == j % 2 && has[i] == res[j]) {
                    to[i] = j;
                    res[j] = -1;
                    break;
                }
            }
            if (to[i] == -1) {
                ok = false;
                break;
            }
        }
        if (!ok) continue;
        int sm = 0;
        for (int i = 0; i < n; ++i) {
            for (int j = 0; j < i; ++j) {
                if (to[j] > to[i])
                    ++sm;
            }
        }
        // for (int i = 0; i < n; ++i) {
        //     if (res[i].first != -1 || has[i].first != -1) {
        //         ok = false;
        //         break;
        //     }
        // }
        if (!ok) continue;
        ans = min(ans, sm);
    }
    if (ans == 1e9) ans = -1;
    cout << ans << endl;

    return 0;
}


Measured memory_bytes: 256