#include <bits/stdc++.h>
using namespace std;
 
#pragma region Macros
#define Faster ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define ll long long
#define ld long double
#define pii pair<int, int>
#define pll pair<long long, long long>
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define pb push_back
#define ff first
#define ss second
#define endl '\n'
#define yes cout << "YES" << endl
#define no cout << "NO" << endl
#define m1 cout << -1 << endl
#pragma endregion
 
#pragma region Math
const ll MOD = 1e9 + 7;
ll gcd(ll a, ll b) { return __gcd(a, b); }
ll lcm(ll a, ll b) { return (a / gcd(a, b)) * b; }
#pragma endregion
 
void solve() {
    int n;  cin>>n;
    vector<int>a(n), b(n);
    for(auto &it:a) cin>>it;
    for(auto &it:b) cin>>it;
    ll ans=0;
 
    for(int i=0;i<n;i++){
 
        int j=i;
        while(j<n and a[j]>b[i])
            j++;
 
        if(j==n){
            cout<<-1<<endl;
            return;
        }
        for(int z=j; z>i; z--){
            swap(a[z],a[z-1]);
            ans++;
        }
    }
    cout<<ans<<endl;
}
int main() {
    Faster;
    int t = 1;
    cin >> t;
    while (t--) solve();
    return 0;
}

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10
3
1 2 2
1 3 5
3
2 2 1
1 2 3
2
5 1
2 4
6
6 5 4 3 2 1
1 2 3 4 5 6
7
4 7 1 6 2 5 3
1 2 3 4 5 6 7
2
2 1
2 3
4
3 2 2 1
1 2 3 4
4
4 3 2 1
1 3 4 5
5
1 5 4 3 2
2 3 4 5 6
5
10 3 8 6 9
3 6 8 9 10