Problem:
Score : 500 points

Problem Statement

Takahashi has decided to work on K days of his choice from the N days starting with tomorrow.

You are given an integer C and a string S. Takahashi will choose his workdays as follows:

After working for a day, he will refrain from working on the subsequent C days.

If the i-th character of S is x, he will not work on Day i, where Day 1 is tomorrow, Day 2 is the day after tomorrow, and so on.

Find all days on which Takahashi is bound to work.

Constraints

1 \leq N \leq 2 \times 10^5

1 \leq K \leq N

0 \leq C \leq N

The length of S is N.

Each character of S is o or x.

Takahashi can choose his workdays so that the conditions in Problem Statement are satisfied.

Input

Input is given from Standard Input in the following format:

N K C
S

Output

Print all days on which Takahashi is bound to work in ascending order, one per line.

Sample Input 1

11 3 2
ooxxxoxxxoo

Sample Output 1

6

Takahashi is going to work on 3 days out of the 11 days. After working for a day, he will refrain from working on the subsequent 2 days.

There are four possible choices for his workdays: Day 1,6,10, Day 1,6,11, Day 2,6,10, and Day 2,6,11.

Thus, he is bound to work on Day 6.

Sample Input 2

5 2 3
ooxoo

Sample Output 2

1
5

There is only one possible choice for his workdays: Day 1,5.

Sample Input 3

5 1 0
ooooo

Sample Output 3

There may be no days on which he is bound to work.

Sample Input 4

16 4 3
ooxxoxoxxxoxoxxo

Sample Output 4

11
16

Solution in Go (1.6) (judge verdict: Accepted)

package main

import (
	"bufio"
	"fmt"
	"io"
	"os"
	"strconv"
	"strings"
)

func main() {
	solve(os.Stdin, os.Stdout)
}

func solve(in io.Reader, out io.Writer) {
	bs := NewBufScanner(in)
	bw := NewBufWriter(out)
	defer bw.w.Flush()
	n, k, c := bs.IntScan(), bs.IntScan(), bs.IntScan()
	s := strings.Split(bs.Scan(), "")

	l := make([]string, n)
	r := make([]string, n)

	var index int
	var lCount int
	lPos := []int{}
	var rCount int

	index = 0
	for {
		if s[index] == "o" {
			l[index] = "o"
			lCount++
			lPos = append(lPos, index)
			index += c
		}
		index++
		if index >= n {
			break
		}
	}

	index = n - 1
	for {
		if s[index] == "o" {
			ok := true
			for i:=1; i<=c; i++ {
				if index + i >= n {
					break
				}
				if r[index+i] == "o" {
					ok = false
					break
				}
			}
			if ok {
				rCount++
				r[index] = "o"
			}
		}
		index--
		if index < 0 {
			break
		}
	}

	if lCount == rCount && lCount == k {
		for _, i := range lPos {
			if l[i] == "o" && l[i] == r[i] {
				bw.Printf("%v\n", i+1)
			}
		}
	}
}

// BufScanner original scanner
type BufScanner struct {
	s *bufio.Scanner
}

// NewBufScanner constructer
func NewBufScanner(in io.Reader) *BufScanner {
	s := bufio.NewScanner(in)
	s.Buffer(make([]byte, 1024), 1e+9)
	s.Split(bufio.ScanWords)
	return &BufScanner{
		s: s,
	}
}

// Scan Scan Data
func (b *BufScanner) Scan() string {
	b.s.Scan()
	return b.s.Text()
}

// IntScan Scan Data
func (b *BufScanner) IntScan() int {
	v, err := strconv.Atoi(b.Scan())
	if err != nil {
		panic(err)
	}
	return v
}

// BufWriter original writer
type BufWriter struct {
	w *bufio.Writer
}

// NewBufWriter constructer
func NewBufWriter(out io.Writer) *BufWriter {
	w := bufio.NewWriter(out)
	return &BufWriter{
		w: w,
	}
}

// Printf Output file
func (b *BufWriter) Printf(format string, a ...interface{}) {
	fmt.Fprintf(b.w, format, a...)
}