#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <utility>
#include <tuple>
#include <cstdint>
#include <cstdio>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <deque>
#include <unordered_map>
#include <unordered_set>
#include <bitset>
#include <cctype>
#include <functional>
#include <ctime>
#include <cmath>
#include <limits>
#include <numeric>
#include <type_traits>
#include <iomanip>
#include <float.h>
#include <math.h>
using namespace std;
using ll = long long;
unsigned euclidean_gcd(unsigned a, unsigned b) {
    if (a < b) return euclidean_gcd(b, a);
    unsigned r;
    while ((r = a % b)) {
        a = b;
        b = r;
    }
    return b;
}

ll ll_gcd(ll a, ll b) {
    if (a < b) return ll_gcd(b, a);
    ll r;
    while ((r = a % b)) {
        a = b;
        b = r;
    }
    return b;
}

class UnionFind {
public:
    vector <ll> par;
    vector <ll> siz;
    UnionFind(ll sz_) : par(sz_), siz(sz_, 1LL) {
        for (ll i = 0; i < sz_; ++i) par[i] = i;
    }
    void init(ll sz_) {
        par.resize(sz_);
        siz.assign(sz_, 1LL);
        for (ll i = 0; i < sz_; ++i) par[i] = i;
    }
    ll root(ll x) {
        while (par[x] != x) {
            x = par[x] = par[par[x]];
        }
        return x;
    }
    bool merge(ll x, ll y) {
        x = root(x);
        y = root(y);
        if (x == y) return false;
        if (siz[x] < siz[y]) swap(x, y);
        siz[x] += siz[y];
        par[y] = x;
        return true;
    }

    bool issame(ll x, ll y) {
        return root(x) == root(y);
    }

    ll size(ll x) {
        return siz[root(x)];
    }
};

long long modpow(long long a, long long n, long long mod) {
    long long res = 1;
    while (n > 0) {
        if (n & 1) res = res * a % mod;
        a = a * a % mod;
        n >>= 1;
    }
    return res;
}

long long modinv(long long a, long long mod) {
    return modpow(a, mod - 2, mod);
}

int main() {
    ll n;
    cin >> n;
    vector<ll> o(n);
    vector<ll> u(n);
    for (int i = 0; i < n; i++) {
        cin >> o[i];
    }
    for (int i = 0; i < n; i++) {
        cin >> u[i];
    }
    for (int i = 0; i < n; i++) {
        if (i % 2 == 1) {
            ll c = o[i];
            o[i] = u[i];
            u[i] = c;
        }
    }
    ll ans = 1234567890;
    for (int bit = 0; bit < (1 << n); bit++) {
        ll us = 0;
        for (int i = 0; i < n; i++) {
            if (bit&(1 << i))us++;
        }
        
        if (us != n / 2)continue;
        vector<ll> z(n/2);
        vector<ll> x(n-n / 2);
        vector<ll> zz(n / 2);
        vector<ll> xx(n - n / 2);
        ll znow = 0;
        ll xnow = 0;
        for (int i = 0; i < n; i++) {
            if (bit & (1 << i)) {
                z[znow] = u[i];
                zz[znow] = i;
                znow++;
            }
            else {
                x[xnow] = o[i];
                xx[xnow] = i;
                xnow++;
            }
        }
        sort(z.begin(), z.end());
        sort(x.begin(), x.end());
        ll fl = 0;
        for (int i = 0; i < n/2; i++) {
            if (i + 1 != x.size()) {
                if (z[i] > x[i + 1])fl = 1;
            }
        }
        for (int i = 0; i < n/2; i++) {
            if (z[i] < x[i])fl = 1;
        }
        if (fl != 0)continue;
        ll zans = 0;
        vector<ll> au(n);
        sort(zz.begin(), zz.end());
        sort(xx.begin(), xx.end());
        for (int i = 0; i < n/2; i++) {
            for (int j = 0; j < n/2; j++) {
                if (zz[j] != -1 && u[zz[j]] == z[i]) {
                    au[i * 2 + 1] = zz[j];
                    zz[j] = -1;
                    break;
                }
            }
        }
        
        for (int i = 0; i < n-n / 2; i++) {
            for (int j = 0; j < n-n / 2; j++) {
                if (xx[j]!=-1&&o[xx[j]] == x[i]) {
                    au[i * 2] = xx[j];
                    xx[j] = -1;
                    break;
                }
            }
        }
        for (int i = 0; i < n; i++) {
            for (int j = i+1; j < n; j++) {
                if (au[i] > au[j])zans++;
            }
        }
        ans = min(ans, zans);
    }
    if (ans == 1234567890)cout << -1 << endl;
    else cout << ans << endl;
}

Measured memory_bytes: 3612