s = input()
n = int(len(s))
ans = 10**10
for i in range(n):
    for j in range(i + 1, n):
        for k in range(j + 1, n):
            if 'c' == s[i] and 'w' == s[j] == s[k]:
                ans = min(ans, k - i + 1)
print(ans if ans != 10**10 else -1)