#include <iostream>
#include <iomanip>
#include <cmath>
#include <algorithm>
#include <vector>
#include <set>
#include <unordered_set>
#include <map>
#include <unordered_map>
#include <random>
#include <chrono>
#include <string>
#include <bitset>
#include <cassert>
#include <queue>
#include <memory>

//#pragma comment(linker, "/STACK:16777216")
//#pragma GCC optimize("O3")
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("unswitch-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,sse4.1,sse4.2,abm,mmx,avx,avx2,popcnt,tune=native")

using namespace std;

//mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());

#define ll long long
#define ull unsigned long long
//#define double long double
//#define int ll
//#define int ull
//#define int short
//#define int unsigned short
//#define int unsigned int
#define mp make_pair
#define F first
#define S second
#define pii pair<int, int>
#define hash hash228
const int SZ = 2e5 + 4;
const double EPS = 1e-7;
const int mod = 998244353;
const int hashpow = 127;
const int inf = 2e9;

struct custom_hash {
    static uint64_t splitmix64(uint64_t x) {
        // http://xorshift.di.unimi.it/splitmix64.c
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }

    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};

int n, k;
string s;

void read() {
    cin >> n >> k >> s;
}

void solve() {
    vector<set<int>> ans;
    int sum = 0;
    while (true) {
        set<int> tmp;
        for (int j = 0; j < n - 1; ++j) {
            if (s[j] == 'R' && s[j + 1] == 'L') {
                swap(s[j], s[j + 1]);
                tmp.insert(j);
                ++sum;
                ++j;
            }
        }
        if (tmp.empty()) break;
        ans.push_back(tmp);
    }

    if (sum < k || k < ans.size()) {
        cout << -1;
        return;
    }

    int tmp = 0;
    bool z = true;
    for (auto &u : ans) {
        if (z) {
            if (tmp + 1 + sum - u.size() >= k) {
                cout << u.size() << " ";
                for (auto v : u) {
                    cout << v + 1 << " ";
                }
                cout << "\n";
                sum -= u.size();
                ++tmp;
            } else {
                int x = tmp + 1 + sum - k;

                int j = 0;
                if (x) {
                    cout << x << " ";
                    for (auto v : u) {
                        cout << v + 1 << " ";
                        ++j;
                        if (j == x) break;
                    }
                    cout << "\n";
                }

                int q = 0;
                for (auto v : u) {
                    if (q >= j) {
                        cout << 1 << " " << v + 1 << "\n";
                    }
                    ++q;
                }
                z = false;
            }
        } else {
            for (auto v : u) {
                cout << 1 << " " << v + 1 << "\n";
            }
        }
    }
}

signed main() {

#ifdef __LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#else
    ios_base::sync_with_stdio(0);
    cin.tie(0);
#endif

//    int t;
//    cin >> t;
//    for (int i = 0; i < t; ++i) {
        read();
        solve();
//    }

    return 0;
}