// 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
	if strings.HasPrefix(s, "o") {
		ans = append(ans, "1")
	}
	w := strings.SplitAfter(s, "xo")
	l := 0
	for i := 0; i < len(w); i++ {
		if !strings.HasSuffix(w[i], "xo") {
			break
		}
		x := l + len(w[i])
		ans = append(ans, strconv.Itoa(x))
		l = x
	}
	fmt.Println(len(ans))
	fmt.Println(strings.Join(ans, " "))
}