S=input()
stack=''
i=0
j=1
ans=len(S)

found=0
while i<len(S)+1:
    while j<len(S)+1:
        x=S[i:j]
        tmp=['c','w','w']
        for y in x:
            if y==tmp[0]:tmp.pop(0)
        if tmp==[]:
            found=1
            i+=1
            ans=min(ans,len(x))#update
        else:
            j+=1
    i+=1
if found:print(ans)
else:print(-1)