import sys
if sys.platform =='ios':
	import clipboard
	a=clipboard.get()
	a = a.split('\n')
	text = '\n'.join(a)
	with open('input_file.txt','w') as f:
		f.write(text)
	sys.stdin = open('input_file.txt')
	
s = input()
n = len(s)
ans = 10**8
for i in range(n):
	for j in range(i+1,n):
		for l in range(j+1,n):
			if s[i] == "c" and s[j] == "w" and s[l] == "w":
				ans = min(ans,l-i+1)
				
if ans == 10**8:
	exit(print(-1))
print(ans)