S = input()
s = len(S)

L = []
for i in range(s):
    for j in range(i+1, s):
        for k in range(j+1, s):
            if S[i] + S[j] + S[k] == 'cww':
                L += [k - i + 1]
                break

print(min(L) if len(L) != 0 else -1)