#include <bits/stdc++.h>
using namespace std;
int a[3005];
vector<vector<int> > b;
int cnt;
int main() {
  ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  int n, k;
  cin >> n >> k;
  for (int i = 0; i < n; i++) {
    char c;
    cin >> c;
    if (c == 'R')
      a[i] = 1;
    else
      a[i] = 0;
  }
  for (int i = 0; i < n; i++) {
    vector<int> t;
    for (int j = 0; j < n - 1; j++) {
      if (a[j] == 1) {
        if (a[j + 1] == 0) {
          t.push_back({j});
          cnt++;
          swap(a[j], a[j + 1]);
          j++;
        }
      }
    }
    if (t.size()) {
      b.push_back(t);
    } else {
      break;
    }
  }
  if (b.size() <= k && k <= cnt) {
    int additional = k - b.size();
    for (int i = 0; i < b.size(); i++) {
      while (b[i].size() > 1 && additional) {
        cout << "1 " << b[i].back() + 1;
        b[i].pop_back();
        cout << "\n";
        additional--;
      }
      cout << b[i].size() << " ";
      for (int j : b[i]) {
        cout << j + 1 << " ";
      }
      cout << "\n";
    }
  } else {
    cout << -1;
  }
  return 0;
}
