def cfind(s):
	w1 = s.find('w')
	w2 = s[(w1 + 1):].find('w')
	if w1 != -1 and w2 != -1:
		cww = w1 + w2 + 3
	else:
		cww = 101
	if s.find('c') == -1:
		return cww
	return min(cww, cfind(s[(s.find('c') + 1):]))
	
S = input()
ans = cfind(S[(S.find('c') + 1):])
print(ans) if ans != 101 else print(-1)