S=input()
ans=1000
if len(S)<3:
    print(-1)
else:
    for i in range(len(S)-2):
        if S[i]=='c':
            for j in range(i,len(S)-1):
                if S[j]=='w':
                    for k in range(j+1,len(S)):
                        if S[k]=='w':
                            ans=k-i+1
    if ans==1000:
        print(-1)
    else:
        print(ans)