// No.2773 Wake up Record 1
package main

import (
	"fmt"
	"strconv"
	"strings"
)

func main() {
	var n int
	fmt.Scan(&n)
	var s string
	fmt.Scan(&s)

	var ans []string
	for i, v := range s {
		if string(v) == "o" {
			if i == 0 {
				ans = append(ans, strconv.Itoa(i+1))
			} else if s[i-1:i] == "x" {
				ans = append(ans, strconv.Itoa(i+1))
			}
		}
	}
	fmt.Println(len(ans))
	fmt.Println(strings.Join(ans, " "))
}