Problem: One fine October day a mathematics teacher Vasily Petrov went to a class and saw there n pupils who sat at the <image> desks, two people at each desk. Vasily quickly realized that number n is even. Like all true mathematicians, Vasily has all students numbered from 1 to n.

But Vasily Petrov did not like the way the children were seated at the desks. According to him, the students whose numbers differ by 1, can not sit together, as they talk to each other all the time, distract others and misbehave.

On the other hand, if a righthanded student sits at the left end of the desk and a lefthanded student sits at the right end of the desk, they hit elbows all the time and distract each other. In other cases, the students who sit at the same desk, do not interfere with each other.

Vasily knows very well which students are lefthanders and which ones are righthanders, and he asks you to come up with any order that meets these two uncomplicated conditions (students do not talk to each other and do not bump their elbows). It is guaranteed that the input is such that at least one way to seat the students always exists.

Input

The first input line contains a single even integer n (4 ≤ n ≤ 100) — the number of students in the class. The second line contains exactly n capital English letters "L" and "R". If the i-th letter at the second line equals "L", then the student number i is a lefthander, otherwise he is a righthander.

Output

Print <image> integer pairs, one pair per line. In the i-th line print the numbers of students that will sit at the i-th desk. The first number in the pair stands for the student who is sitting to the left, and the second number stands for the student who is sitting to the right. Separate the numbers in the pairs by spaces. If there are multiple solutions, print any of them.

Examples

Input

6
LLRLLL


Output

1 4
2 5
6 3


Input

4
RRLL


Output

3 1
4 2

Solution (in JAVA):

Solution:
import java.io.*;
import java.util.*;

public class Main {
  
    String fileName = ""; // here you sould write name of input file (for example "input")
    
    void solve() throws IOException {
      int n = readInt();
      char [] arr = readString().toCharArray();
      ArrayList<int[]> ans = new ArrayList();
      int startIndex = 0;
      if(n % 4 == 2) {
        for(int i=0;i<3;i++) {
          ans.add(new int[]{i, i + 3});
        }
        startIndex = 6;
      }
      for(int i=startIndex; i < n; i+=4) {
        ans.add(new int[]{i, i + 2});
        ans.add(new int[]{i + 1, i + 3});
      }
      for(int i=0;i<n/2;i++) {
        if(arr[ans.get(i)[0]] == 'R' && arr[ans.get(i)[1]] == 'L') {
          out.println(ans.get(i)[1] + 1 + " " + (int)(ans.get(i)[0] + 1));
        } else {
          out.println(ans.get(i)[0] + 1 + " " + (int)(ans.get(i)[1] + 1));
        }
      }
    }

    public static void main(String[] args) throws NumberFormatException, IOException {
        new Main().run(); // this is main method of all Java programms 
                          // Here you create a new Class Main and simultaniously run it with method
                          
    }

    void run() throws NumberFormatException, IOException {
        solve();   // there start method solve, where you must write your solution
        out.close();  // it is important line - it is closing output stream
                      // if in your code no line "out.close()", then you output file will be clean
    } 

    BufferedReader in; // if is a class, that connect variable "in" and input stream
    PrintWriter out; // same for output stream

    StringTokenizer tok; // this is tokenizer - 
    String delim = " ";  // and delimiter
      
    
    Main() throws FileNotFoundException {   // this is a constructor of class Main
        try {                               // here you connect all streams with corresponds variables 
            in = new BufferedReader(new FileReader("input.txt"));
            out = new PrintWriter("output.txt");
        } catch (Exception e) {
            if (fileName.isEmpty()) {
                in = new BufferedReader(new InputStreamReader(System.in));
                out = new PrintWriter(System.out);
            } else {
                in = new BufferedReader(new FileReader(fileName + ".in"));
                out = new PrintWriter(fileName + ".out");
            }

        }
        tok = new StringTokenizer("");
    }

    String readLine() throws IOException { // return you a line (obvious)
        return in.readLine();
    }

    String readString() throws IOException { // return you a substring until delimiter
        while (!tok.hasMoreTokens()) {       // for example:
            String nextLine = readLine();    // input : 
            if (null == nextLine) {          // ABCE QWE
                return null;                 // delimiter = " "
            }                                // String a = readString(); a is equal to "ABCE"

            tok = new StringTokenizer(nextLine);
        }
        return tok.nextToken(delim);
    }

    int readInt() throws NumberFormatException, IOException { // get string from input and convert it in Integer
        return Integer.parseInt(readString());
    }

    long readLong() throws NumberFormatException, IOException {// get string from input and convert it in Long
        return Long.parseLong(readString());
    }

    int[] readIntArray(int n) throws NumberFormatException, IOException { 
        int[] a = new int[n];   // get n strings from input and convert it in Integer array
        for (int i = 0; i < n; ++i) {
            a[i] = readInt();
        }
        return a;
    }

    double readDouble() throws NumberFormatException, IOException { // get string from input and convert it in Double
        return Double.parseDouble(readString());
    }
    void sortIntArray(int [] a) {  // sort your Integer array with O(n logn) time 
                                   // It is important because of default Arrays.sort() for int array use QuickSort, which may be very slow :D
        
        Integer[] arr = new Integer[a.length];  
        for (int i = 0; i < a.length; i++) {
            arr[i] = a[i];
        }
        Arrays.sort(arr);
        for (int i = 0; i < a.length; i++) {
            a[i] = arr[i];
        }
    }

    // that is all :D 
}