#include <bits/stdc++.h>
using namespace std;

struct VectorHash {
    size_t operator()(const vector<int>& v) const {
        size_t h = 0;
        for (int x : v) {
            h ^= hash<int>{}(x) + 0x9e3779b9 + (h << 6) + (h >> 2);
        }
        return h;
    }
};

int brute(int N, const vector<pair<int, int>>& A) {
    int M = A.size();

    vector<int> S(M), G(M);

    for (int i = 0; i < M; ++i) {
        S[i] = A[i].first;
        G[i] = A[i].second;
    }

    queue<vector<int>> que;
    unordered_map<vector<int>, int, VectorHash> dist;

    dist[S] = 0;
    que.push(S);

    while (!que.empty()) {
        auto X = que.front();
        que.pop();

        int d = dist[X];

        if (X == G) {
            return d;
        }

        for (int F = 1; F <= N; ++F) {
            int mn = N + 1;

            // F に最も近い距離を求める
            for (int i = 0; i < M; ++i) {
                mn = min(mn, abs(X[i] - F));
            }

            // 同率最小のエレベーターはすべて選択候補
            for (int i = 0; i < M; ++i) {
                if (abs(X[i] - F) != mn) continue;

                // 動かない遷移は不要
                if (X[i] == F) continue;

                auto Y = X;
                Y[i] = F;

                if (!dist.count(Y)) {
                    dist[Y] = d + 1;
                    que.push(Y);
                }
            }
        }
    }

    return -1;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int Q;
    cin >> Q;

    while (Q--) {
        int N, M;
        cin >> N >> M;

        vector<pair<int, int>> A(M);

        for (auto& [s, g] : A) cin >> s;
        for (auto& [s, g] : A) cin >> g;

        // ラベルを付け替えているだけなので、
        // (S_i, G_i) ごとソートしても問題ない
        sort(A.begin(), A.end());

        cout << brute(N, A) << '\n';
    }
}