s = input()

l = len(s)
ans = 1000
for i in range(l):
    for j in range(i + 1, l):
        for k in range(j + 1, l):
            if s[i] == "c" and s[j] == "w" and s[k] == "w":
                ans = min(ans, k - i + 1)

if ans == 1000:
    ans = -1

print(ans)