def f(ss):
	cnt = 0
	for s in ss:
		if s == "c" and cnt == 0:
			cnt += 1
		if s == "w" and (1 <= cnt <= 2):
			cnt += 1
	return cnt == 3
	
S = input()
N = len(S)
ans = 105
for i in range(N):
	for j in range(i + 1, N + 1):
		if f(S[i:j]):
			ans = min(ans, j - i)
			
print(ans) if ans != 105 else print(-1)