#include <bits/stdc++.h>

using ll = long long;
#define int ll

// [a -> b-1]
#define reps(i, a, b) for (int i = (int)(a); i < (int)(b); i++)
// [0 -> a-1]
#define rep(i, a) reps(i, 0, (a))
// [a-1 -> b]
#define rreps(i, a, b) for (int i = (int)((a)-1); i >= (int)(b); i--)
// [a-1 -> 0]
#define rrep(i, a) rreps(i, a, 0)
#define all(v) (v).begin(), (v).end()
// next_permutation(all(v))
#define PERM(v) next_permutation(all(v))
/*sort(all(v));
 * (v).erase(unique(all(v)), v.end())*/
#define UNIQUE(v)\
	sort(all(v));\
	(v).erase(unique(all(v)), v.end())
#define MINV(v) min_element(all(v))
#define MAXV(v) max_element(all(v))
#define MIN3(a, b, c) min(min(a, b), c)
#define MIN4(a, b, c, d) min(MIN3(a, b, c), d)
#define MIN5(a, b, c, d, e) min(MIN4(a, b, c, d), e)
#define MIN6(a, b, c, d, e, f) min(MIN5(a, b, c, d, e), f)
#define MAX3(a, b, c) max(max(a, b), c)
#define MAX4(a, b, c, d) max(MAX3(a, b, c), d)
#define MAX5(a, b, c, d, e) max(MAX4(a, b, c, d), e)
#define MAX6(a, b, c, d, e, f) max(MAX5(a, b, c, d, e), f)
// b is [a, c)
#define RANGE(a, b, c) ((a) <= (b) && (b) < (c))
// c is [a, e) && d is [b, f)
#define RANGE2D(a, b, c, d, e, f) (RANGE((a), (c), (e)) && RANGE((b), (d), (f)))
#define chmin(a, b) a = min(a, (b))
#define chmin3(a, b, c) a = MIN3(a, (b), (c))
#define chmin4(a, b, c, d) a = MIN4(a, (b), (c), (d))
#define chmin5(a, b, c, d, e) a = MIN5(a, (b), (c), (d), (e))
#define chmin6(a, b, c, d, e, f) a = MIN6(a, (b), (c), (d), (e), (f))
#define chmax(a, b) a = max(a, (b))
#define chmax3(a, b, c) a = MAX3(a, (b), (c))
#define chmax4(a, b, c, d) a = MAX4(a, (b), (c), (d))
#define chmax5(a, b, c, d, e) a = MAX5(a, (b), (c), (d), (e))
#define chmax6(a, b, c, d, e, f) a = MAX6(a, (b), (c), (d), (e), (f))
#define fcout cout << fixed << setprecision(15)
#define YES(f) cout << ((f) ? YES_STR : NO_STR) << endl;

using namespace std;

#ifndef LOCAL_DEBUG_OPTION
namespace debug_print_n{
struct DebugPrint {
	template<class T, class U = remove_const_t<remove_reference_t<T>>>
	static enable_if_t<is_integral<U>::value && !is_same<U, bool>::value && !is_same<U, char>::value> DUMP_SUB_FUNCTION(T x) {
		cerr << x;
	}
	template<class T, class U = remove_const_t<remove_reference_t<T>>>
	static enable_if_t<is_same<U, bool>::value> DUMP_SUB_FUNCTION(T x) {
		if (x) cerr << "True";
		else cerr << "False";
	}
	template<class T, class U = remove_const_t<remove_reference_t<T>>>
	static enable_if_t<is_same<U, char>::value> DUMP_SUB_FUNCTION(T x) {
		cerr << '\'' << x << '\'';
	}
	template<class T, class U = remove_const_t<remove_reference_t<T>>>
	static enable_if_t<is_same<U, string>::value> DUMP_SUB_FUNCTION(T x) {
		cerr << '\"' << x << '\"';
	}
	template<class T>
	static enable_if_t<is_same<T, const char*>::value> DUMP_SUB_FUNCTION(T x) {
		cerr << string(x);
	}
	template<class T>
	static enable_if_t<true> DUMP_SUB_FUNCTION(vector<T> x) {
		cerr << '{';
		for (size_t i = 0; i < x.size(); i++) {
			if (i) cerr << ", ";
			DUMP_SUB_FUNCTION(x[i]);
		}
		cerr << '}';
	}
	template<class T, size_t N>
	static enable_if_t<true> DUMP_SUB_FUNCTION(array<T, N> x) {
		cerr << '{';
		for (size_t i = 0; i < x.size(); i++) {
			if (i) cerr << ", ";
			DUMP_SUB_FUNCTION(x[i]);
		}
		cerr << '}';
	}
	template<class T>
	static enable_if_t<true> DUMP_SUB_FUNCTION(set<T> x) {
		cerr << '[';
		size_t i = 0;
		for (auto itr = x.begin(); itr != x.end(); itr++, i++) {
			if (i) cerr << ", ";
			DUMP_SUB_FUNCTION(*itr);
		}
		cerr << ']';
	}
	template<class T, class U>
	static enable_if_t<true> DUMP_SUB_FUNCTION(map<T, U> x) {
		cerr << '[';
		size_t i = 0;
		for (auto itr = x.begin(); itr != x.end(); itr++, i++) {
			if (i) cerr << ", ";
			DUMP_SUB_FUNCTION(itr->first);
			cerr << " : ";
			DUMP_SUB_FUNCTION(itr->second);
		}
		cerr << ']';
	}
	template<class T, class U = remove_const_t<remove_reference_t<T>>>
	static enable_if_t<is_floating_point<U>::value> DUMP_SUB_FUNCTION(T x) {
		cerr << fixed << setprecision(5) << x;
	}
	template<class T, class U>
	static enable_if_t<true> DUMP_SUB_FUNCTION(pair<T, U> p) {
		cerr << '(';
		DUMP_SUB_FUNCTION(p.first);
		cerr << ", ";
		DUMP_SUB_FUNCTION(p.second);
		cerr << ')';
	}
	template<int num = 0, class... Args>
	static enable_if_t<num == sizeof...(Args)> DUMP_SUB_FUNCTION(tuple<Args...> t) {
		if (num) cerr << ')';
	}
	template<int num = 0, class... Args>
	static enable_if_t<num < sizeof...(Args)> DUMP_SUB_FUNCTION(tuple<Args...> t) {
		if (num == 0) cerr << '(';
		DUMP_SUB_FUNCTION(get<num>(t));
		if (num + 1 < sizeof...(Args)) cerr << ", ";
		DUMP_SUB_FUNCTION<num+1>(t);
	}
	template<long unsigned N>
	static enable_if_t<true> DUMP_SUB_FUNCTION(bitset<N> x) {
		cerr << x;
	}
};
void dump() {
	cerr << endl;
}
template<class Head, class... Tail>
void dump(Head&& head, Tail&&... tail) {
	DebugPrint::DUMP_SUB_FUNCTION(head);
	if (sizeof...(Tail) != 0) {
		cerr << ' ';
	}
	dump(forward<Tail>(tail)...);
}
} // namespace debug_print_n
using debug_print_n::dump;
#else
template<class... Args> void dump(Args&&... args) { }
#endif

signed main(){
	int N; cin >> N;
	vector<int> A(N), B(N);
	rep(i, N) cin >> A[i];
	rep(i, N) cin >> B[i];
	vector<int> idx(1 << N);
	rep(i, 1 << N) idx[i] = i;
	sort(all(idx), [](auto a, auto b) {return __builtin_popcountll(a) < __builtin_popcountll(b);});
	vector<vector<int>> dp(1 << N, vector<int>(N, 1e9));
	reps(i, 1, N+1) {
		dp[1 << (i-1)][i-1] = i - 1;
	}
	auto num = [&](int i, int j) {
		if ((i - j) % 2 == 0) return A[i];
		return B[i];
	};
	for (int i : idx) {
		if (i == 0) continue;
		rep(j, N) {
			rep(k, N) {
				if (i & (1 << k)) continue;
				int p = __builtin_popcountll(i) - 1;
				int m = ~((1 << (k+1)) - 1);
				int id = k + __builtin_popcount(i & m);
				if (num(k, p+1) < num(j, p)) continue;
				chmin(dp[i | (1 << k)][k], dp[i][j] + abs(id - (p+1)));
			}
		}
	}
	auto r = *min_element(dp.back().begin(), dp.back().end());
	if (r == 1e9) cout << -1 << endl;
	else cout << r << endl;
}


Measured memory_bytes: 51456