#define _CRT_SECURE_NO_WARNINGS
#define _SCL_SECURE_NO_WARNINGS
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cassert>
#include <iostream>
#include <string>
#include <vector>
#include <list>
#include <utility>
#include <algorithm>
#include <functional>
#include <cmath>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <iomanip>
#include <sstream>
#include <bitset>
#include <limits>
#include <numeric>
#include <valarray>
#include <fstream>
#include <array>
#include <random>
#include <unordered_set>
#include <unordered_map>

using namespace std;
using uint = uint32_t;
using LL = int64_t;
using ULL = uint64_t;
using PP = pair<LL, LL>;
template <typename T> using PriorityQ = priority_queue<T, vector<T>, greater<T> >;
#define REP(i, a, n) for(LL i = (a), i##_max_ = (n); i < i##_max_; ++i)
#define REM(i, a, n) for(LL i = (LL)(n) - 1, i##_min_ = (a); i >= i##_min_; --i)
#define FLOAT fixed << setprecision(16)
#define SPEEDUP { cin.tie(NULL); ios::sync_with_stdio(false); }
const int INF = 0x3FFFFFFF;
const LL INFLL = 0x3FFFFFFF3FFFFFFF;
const double INFD = 1.0e+308;
const double EPS = 1.0e-9;

void YesNo(bool b) { cout << (b ? "Yes" : "No") << endl; }
void YESNO(bool b) { cout << (b ? "YES" : "NO") << endl; }
template <class T, class U> istream& operator>>(istream& ist, pair<T, U>& right) { return ist >> right.first >> right.second; }
template <class T, class U> ostream& operator<<(ostream& ost, const pair<T, U>& right) { return ost << right.first << ' ' << right.second; }
template <class T, class TCompatible, size_t N> void Fill(T(&dest)[N], const TCompatible& val) { fill(dest, dest + N, val); }
template <class T, class TCompatible, size_t M, size_t N> void Fill(T(&dest)[M][N], const TCompatible& val) { for (int i = 0; i < M; ++i) Fill(dest[i], val); }
template <class T> T Next() { T buf; cin >> buf; return buf; }
istream& Ignore(istream& ist) { string s; ist >> s; return ist; }
bool Inside(int i, int j, int h, int w) { return i >= 0 && i < h && j >= 0 && j < w; }

#ifdef ONLY_MY_ENVIR
#include "IntMod.h"
#include "Algebraic.h"
#include "BinaryMatrix.h"
#include "BinaryTree.h"
#include "Bipartite.h"
#include "BIT.h"
#include "DynamicMod.h"
#include "Factorization.h"
#include "FFT.h"
#include "FlowSolver.h"
#include "Graph.h"
#include "LazySegmentTree.h"
#include "Math.h"
#include "Matrix.h"
#include "MinCostFlowSolver.h"
#include "MinMax.h"
#include "Numbers.h"
#include "Polynomial.h"
#include "Position.h"
#include "Range.h"
#include "Rational.h"
#include "SegmentTree.h"
#include "SegmentTree2D.h"
#include "SlidingWindow.h"
#include "StringSeaching.h"
#include "SuffixArray.h"
#include "Tree.h"
#include "UnionFind.h"
#endif

#ifdef __GNUC__
typedef __int128 LLL;
istream& operator>>(istream& ist, __int128& val) { LL tmp; ist >> tmp; val = tmp; return ist; }
ostream& operator<<(ostream& ost, __int128 val) { LL tmp = val; ost << tmp; return ost; }
#endif

int N;
int A[18];
int B[18];
int C[18];
int sub(int s) {
	int odd = 0;
	int even = 0;
	REP(k, 0, N) {
		if ((s >> k) & 1) {
			++(k % 2 == 0 ? even : odd);
		}
	}

	if (even != odd) return INF;
	
	vector<int> sorted;
	vector<int> original;

	REP(k, 0, N) {
		bool flip = (s >> k) & 1;
		if (flip) {
			C[k] = B[k];
		} else {
			C[k] = A[k];
		}

		original.push_back(C[k]);
		sorted.push_back(C[k]);
	}
	sort(sorted.begin(), sorted.end());

	vector<bool> used(N, false);
	vector<int> perm(N);
	REP(i, 0, N) {
		int parity = (i % 2) ^ ((s >> i) & 1);
		int p = -1;
		REP(k, 0, N) {
			if (used[k]) continue;
			if (sorted[k] != original[i]) continue;
			if (k % 2 != parity) continue;
			p = k;
			break;
		}

		if (p == -1) return INF;
		used[p] = true;
		perm[i] = p;
	}

	int cnt = 0;
	REP(i, 0, N) {
		REP(j, i + 1, N) {
			if (perm[i] > perm[j]) ++cnt;
		}
	}
	return cnt;
}

int main() {
	cin >> N;
	REP(i, 0, N) {
		cin >> A[i];
	}
	REP(i, 0, N) {
		cin >> B[i];
	}

	int mn = INF;
	REP(s, 0, 1 << N) {
		mn = min(mn, sub(s));
	}
	cout << (mn == INF ? -1 : mn) << endl;
	return 0;
}

Measured memory_bytes: 256