S = input()
lens = len(S)
length = -1
for i,c in enumerate(S):
    if c == "c":
        if i + 2 <= lens:
            count = 1
            wcnt = 0
            for w in S[i + 1:]:
                count+=1
                if w == "w":
                    wcnt+=1
                    if wcnt == 2:
                        if length == -1 or length > count:
                            length = count
                            break

print(length)