S = input()
lens = len(S)
for i,c in enumerate(S):
    chiwawa = False
    if c == "c":
        start = i
        wcnt = 0
        length = 1
        if i + 2 <= lens:
            for j,c2 in enumerate(S[i + 1:]):
                length+=1
                if c2 == "w":
                    wcnt+=1
                    if wcnt == 2:
                        chiwawa = True
                        break
    if chiwawa:
        break
else:
    length = -1
print(length)