package main

import (
	"fmt"
	"regexp"
)

func main() {
	var S string
	fmt.Scan(&S)
	reg := regexp.MustCompile(`c.*?w.*w`)
	s := reg.FindString(S)
	l := -1
	if len(s) > 0 {
		l = len(s)
	}
	fmt.Println(l)
}