s=input()

count=[0 for i in range(len(s)-1)]
for j in range(len(s)-2):
    a=''
    for i in range (j,len(s)):
        if a=='' and s[i]=='c':
            a+='c'
            count[j]+=1
        elif a=='c' and s[i]=='w':
            a+='w'
            count[j]+=1
        elif a=='cw' and s[i]=='w':
            a+='w'
            count[j]+=1
            break
        elif a=='c' or a=='cw':
            count[j]+=1
    if a!='cww':
        count[j]=-1

answer=1000
for i in range(len(count)):
    if count[i]<answer and count[i]>0:
        answer=count[i]

if answer==1000:
    print(-1)
else:
    print(answer)