#include <bits/stdc++.h>
using namespace std;
template <typename Arg1>
void __f(const char* name, Arg1&& arg1) {
  cout << name << " : " << arg1 << "\n";
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args) {
  const char* comma = strchr(names + 1, ',');
  cout.write(names, comma - names) << " : " << arg1 << " | ";
  __f(comma + 1, args...);
}
inline int sbt(int x) { return __builtin_popcount(x); }
inline long long gl(long long a, long long b) { return (b - a + 1); }
inline long long mul(long long a, long long b,
                     long long m = (long long)(1e9 + 7)) {
  return ((a % m) * (b % m)) % m;
}
inline long long add(long long a, long long b,
                     long long m = (long long)(1e9 + 7)) {
  return (a + b) % m;
}
inline long long sub(long long a, long long b,
                     long long m = (long long)(1e9 + 7)) {
  return (a - b + m) % m;
}
long long fastpow(long long a, long long b) {
  long long res = 1;
  while (b > 0) {
    if (b & 1) res = mul(res, a);
    a = mul(a, a);
    b >>= 1;
  }
  return res;
}
long long modinv(long long a) { return fastpow(a, (long long)(1e9 + 7) - 2); }
void get_ac() {
  long long n, k;
  cin >> n >> k;
  string s;
  cin >> s;
  vector<vector<long long>> v;
  bool f;
  long long mink = 0, maxk = 0;
  while (1) {
    f = 0;
    vector<long long> va;
    for (int i = 0; i < n - 1; i++) {
      if (s[i] == 'R' && s[i + 1] == 'L') {
        swap(s[i], s[i + 1]);
        f = 1;
        va.push_back(i);
        i++;
      }
    }
    if (!f) break;
    v.push_back(va);
    maxk += (long long)(va.size());
    mink++;
  }
  if (k < mink || k > maxk) {
    cout << -1;
    return;
  }
  long long i = 0, j = 0;
  while (k > mink - i) {
    cout << 1 << " " << v[i][j] + 1;
    cout << "\n";
    j++;
    if (j == (long long)(v[i].size())) {
      i++;
      j = 0;
    }
    k--;
  }
  for (int l = i; l < mink; l++) {
    cout << ((long long)(v[l].size()) - j) << " ";
    for (int m = j; m < (long long)(v[l].size()); m++) {
      cout << v[l][m] + 1 << " ";
    }
    j = 0;
    cout << "\n";
  }
}
int main() {
  cin.sync_with_stdio(false);
  cout.sync_with_stdio(false);
  cin.tie(NULL);
  { get_ac(); }
  return 0;
}
