#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <vector>
#include <iomanip>
#include <sstream>
#include <bitset>
#define ALL(x) (x).begin(), (x).end()
#define sz(a) int(a.size())
#define rep(i,x,n) for(int i=x;i<n;i++)
#define repd(i,x,n) for(int i=x;i<=n;i++)
#define pii pair<int,int>
#define pll pair<long long ,long long>
#define gbtb ios::sync_with_stdio(false),cin.tie(0),cout.tie(0)
#define MS0(X) memset((X), 0, sizeof((X)))
#define MSC0(X) memset((X), '\0', sizeof((X)))
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define eps 1e-6
#define chu(x) cout<<"["<<#x<<" "<<(x)<<"]"<<endl
#define du3(a,b,c) scanf("%d %d %d",&(a),&(b),&(c))
#define du2(a,b) scanf("%d %d",&(a),&(b))
#define du1(a) scanf("%d",&(a));
using namespace std;
typedef long long ll;
ll gcd(ll a, ll b) {return b ? gcd(b, a % b) : a;}
ll lcm(ll a, ll b) {return a / gcd(a, b) * b;}
ll powmod(ll a, ll b, ll MOD) { if (a == 0ll) {return 0ll;} a %= MOD; ll ans = 1; while (b) {if (b & 1) {ans = ans * a % MOD;} a = a * a % MOD; b >>= 1;} return ans;}
ll poww(ll a, ll b) { if (a == 0ll) {return 0ll;} ll ans = 1; while (b) {if (b & 1) {ans = ans * a ;} a = a * a ; b >>= 1;} return ans;}
void Pv(const vector<int> &V) {int Len = sz(V); for (int i = 0; i < Len; ++i) {printf("%d", V[i] ); if (i != Len - 1) {printf(" ");} else {printf("\n");}}}
void Pvl(const vector<ll> &V) {int Len = sz(V); for (int i = 0; i < Len; ++i) {printf("%lld", V[i] ); if (i != Len - 1) {printf(" ");} else {printf("\n");}}}
inline long long readll() {long long tmp = 0, fh = 1; char c = getchar(); while (c < '0' || c > '9') {if (c == '-') fh = -1; c = getchar();} while (c >= '0' && c <= '9') tmp = tmp * 10 + c - 48, c = getchar(); return tmp * fh;}
inline int readint() {int tmp = 0, fh = 1; char c = getchar(); while (c < '0' || c > '9') {if (c == '-') fh = -1; c = getchar();} while (c >= '0' && c <= '9') tmp = tmp * 10 + c - 48, c = getchar(); return tmp * fh;}
const int maxn = 1010;
const int inf = 0x3f3f3f3f;
/*** TEMPLATE CODE * * STARTS HERE ***/
int n;
int a[maxn];
int b[maxn];
pii c[maxn];
int d[maxn];

int solve(int x)
{
	repd(i, 0, n - 1)
	{
		if (x & (1 << i))
		{
			c[i].fi = b[i];
			c[i].se = 1;
		} else
		{
			c[i].fi = a[i];
			c[i].se = 0;
		}
		d[i] = c[i].fi;
	}
	sort(d, d + n);
	int res = 0;
	for (int i = n - 1; i >= 0; --i)
	{
		int flag = 1;
		for (int j = i; j >= 0; --j)
		{
			if (c[j].fi == d[i] && (c[j].se == (i - j & 1)))
			{
				flag = 0;
				res += i - j;
				repd(k, j, i - 1)
				{
					c[k + 1].se ^= 1;
					swap(c[k], c[k + 1]);
				}
				flag = 0;
				break;
			}
		}
		if (flag)
		{
			return inf;
		}
	}
	return res;
}
int main()
{
	//freopen("D:\\code\\text\\input.txt","r",stdin);
	//freopen("D:\\code\\text\\output.txt","w",stdout);
	n = readint();
	repd(i, 0, n - 1)
	{
		a[i] = readint();
	}
	repd(i, 0, n - 1)
	{
		b[i] = readint();
	}
	int maxstate = (1 << n) - 1;
	int ans = inf;
	repd(i, 0, maxstate)
	{
		int res = solve(i);
		ans = min(ans, res);
	}
	printf("%d\n", ans == inf ? -1 : ans);

	return 0;
}




Measured memory_bytes: 256