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

string colors[] = {"BG", "BR", "BY", "GR", "GY", "RY"};

bool hasCommmon(string &a, string &b)
{
    if (a[0] == b[0] || a[1] == b[0] || a[0] == b[1] || a[1] == b[1])
        return 1;
    else
        return 0;
}

void solve()
{
    int n, q;
    cin >> n >> q;

    unordered_map<string, vector<int>> mp;
    vector<string> city(n + 1);
    for (int i = 0; i < n; i++)
    {
        string s;
        cin >> s;
        mp[s].push_back(i + 1);
        city[i + 1] = s;
    }

    for (int i = 0; i < 6; i++)
    {
        auto &v = mp[colors[i]];
        sort(v.begin(), v.end());
    }

    while (q--)
    {
        int x, y;
        cin >> x >> y;

        if (x > y)
            swap(x, y);

        string s1 = city[x];
        string s2 = city[y];

        if (hasCommmon(s1, s2))
        {
            cout << abs(x - y) << "\n";
        }
        else
        {
            int ans = 1e9;
            for (int i = 0; i < 6; i++)
            {
                if (colors[i] == s1 || colors[i] == s2)
                    continue;

                auto &v = mp[colors[i]];
                auto it = lower_bound(v.begin(), v.end(), x);
                if (it != v.end())
                {
                    ans = min(ans, abs(x - *it) + abs(*it - y));
                }
                if (it != v.begin())
                {
                    it--;
                    ans = min(ans, abs(x - *it) + abs(*it - y));
                }
            }
            cout << ((ans == 1e9) ? -1 : ans) << "\n";
        }
    }
}

signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int t;
    cin >> t;
    while (t--)
        solve();
    exit(0);
}

#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
using ll = long long;
#define pb push_back
#define popb pop_back
#define lb lower_bound
#define ub upper_bound
#define int long long

int intersect(string a, string b)
{
    if (a[0] == b[0] || a[0] == b[1] || a[1] == b[0] || a[1] == b[1])
        return 1;
    else
        return 0;
}

void solve()
{
    int n, q;
    cin >> n >> q;
    unordered_map<string, vector<int>> mp;
    vector<string> col(n + 1);
    for (int i = 0; i < n; i++)
    {
        string s;
        cin >> s;
        mp[s].pb(i);
        col[i] = s;
    }
    for (auto it : mp)
        sort(it.second.begin(), it.second.end());
    while (q--)
    {
        int x, y;
        cin >> x >> y;
        if (x > y)
            swap(x, y);

        x--;
        y--;
        string a, b;

        a = col[x];
        b = col[y];

        if (intersect(a, b))
        {
            cout << abs(x - y) << endl;
            continue;
        }
        int ans = 1e9;
        for (auto it : mp)
        {
            if (it.first == a || it.first == b)
                continue;
            auto pos = lower_bound(it.second.begin(), it.second.end(), x);
            if (pos != it.second.end())
                ans = min(ans, abs(*pos - x) + abs(*pos - y));
            if (pos != it.second.begin())
            {
                pos--;
                ans = min(ans, abs(*pos - x) + abs(*pos - y));
            }
        }
        if (ans == 1e9)
            cout << -1 << endl;
        else
            cout << ans << endl;
    }
}

signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int tt;
    cin >> tt;
    while (tt--)
        solve();
}