subarray with zero sum

/**
 *    author:  compounding
 *    created: 2024-12-25 23:37:48
 **/
#include <bits/stdc++.h>
using namespace std;
mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());
#define NeedForSpeed                  \
    ios_base::sync_with_stdio(false); \
    cin.tie(NULL);                    \
    cout.tie(NULL);
#define int long long
#define all(x) (x).begin(), (x).end()
typedef vector<int> vi;
typedef vector<bool> vb;
typedef vector<vi> vvi;
typedef vector<pair<int, int>> vpi;
#define f first
#define s second
#define yes cout << "YES" << endl
#define no cout << "NO" << endl
#define endl "\n"
const int mod = 1000000007;
int gcd(int a, int b) { return b == 0 ? a : gcd(b, a % b); }
void solve()
{
    // subarray with sum 0, minimum size
    int n;
    cin >> n;
    string s;
    cin >> s;
    map<pair<int, int>, int> mp;
    mp[{0, 0}] = 0;
    int hor = 0, ver = 0, start = -1, end = -1, min_len = LLONG_MAX;
    for (int i = 0; i < n; i++)
    {
        if (s[i] == 'L')
        {
            hor--;
        }
        else if (s[i] == 'R')
        {
            hor++;
        }
        else if (s[i] == 'U')
        {
            ver++;
        }
        else if (s[i] == 'D')
        {
            ver--;
        }
        // if they have same value of hor, ver means in b/w we have a subarray with sum 0
        if (mp.count({hor, ver}))
        {
            int prev_index = mp[{hor, ver}];
            if (i - prev_index < min_len)
            {
                min_len = i - prev_index;
                start = prev_index + 1;
                end = i + 1;
            }
        }
        mp[{hor, ver}] = i + 1;
    }
    if (start == -1)
    {
        cout << -1 << endl;
    }
    else
    {
        cout << start << " " << end << endl;
    }
    return;
}

signed main()
{
    NeedForSpeed;
    int t = 1;
    cin >> t;
    while (t--)
    {
        solve();
    }
    return 0;
}