package main

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

var sc = bufio.NewScanner(os.Stdin)

func nextInt() int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return i
}
func nextStr() string {
	sc.Scan()
	return sc.Text()
}
func get(n int) []string {
	inputs :=
		make([]string, n)
	for index := range inputs {
		inputs[index] = nextStr()
	}
	return inputs
}
func main() {
	sc.Split(bufio.ScanWords)
	str := nextStr()
	chiwawa := -1
	cc := make(map[int]int)
	wc := make(map[int]int)
	ccount, wcount := 0, 0
	for i, c := range str {
		if c == 'c' {
			cc[ccount] = i
			ccount++
		} else if c == 'w' {
			wc[wcount] = i
			wcount++
		}
	}
	if len(wc) < 2 {
		fmt.Println(chiwawa)
	}
	for i := len(wc) - 2; i > -1; i-- {
		for _, index := range cc {
			if index > wc[i] {
				break
			}
			if index-wc[i+1] < chiwawa || chiwawa == -1 {
				chiwawa = wc[i+1] - index + 1
			}
		}
	}
	fmt.Println(chiwawa)
}