S=input()


ANS=1<<60
for i in range(len(S)):
    for j in range(i+1,len(S)+1):
        T=S[i:j]
        flag=0

        for t in T:
            if t=="c" and flag==0:
                flag+=1
            elif t=="w" and flag>=1:
                flag+=1

        if flag>=3:
            ANS=min(ANS,len(T))

if ANS==1<<60:
    print(-1)
else:
    print(ANS)