package main

import (
	"fmt"
	"regexp"
	"strings"
)

func main() {
	var S string
	fmt.Scan(&S)

	l := -1
	reg := regexp.MustCompile(`^c[^c]*?w.*?w`)
	for {
		index := strings.Index(S, "c")
		if index == -1 {
			break
		}
		S = S[index:]
		s := reg.FindString(S)
		slen := len(s)
		if slen > 0 && (slen < l || l == -1) {
			l = slen
		}
		S = S[1:]
	}
	fmt.Println(l)
}