# codidng=utf-8:

s = str(input())
chiwawa = list()
for string in s:
    chiwawa.append(string)

c = 0
w1 = 0
w2 = 0
if len(chiwawa) < 3:
    print(-1)
else:
    del chiwawa[:chiwawa.index("c")]
    for ch1 in chiwawa:
        if ch1 == "c":
            c = chiwawa.index(ch1)
            del chiwawa[:c]
            break
            
    for ch2 in chiwawa:
        if ch2 == "w":
            w1 = chiwawa.index(ch2)
            del chiwawa[:w1]
            break
    
    for ch3 in chiwawa:
        if ch3 == "w":
            w2 = chiwawa.index(ch3)
            del chiwawa[:w2]
            break
    
    ans = c + w1 + w2 + 1
    print(ans)