s = input()
ret = float('inf')
for i in range(len(s)+1):
    for j in range(i+1, len(s)+1):
        t = s[i:j]
        if t.count('c')>=1 and t.count('w')>=2:
            if t.index('c')<t.index('w'):
                ret = min(ret, len(t))
print(ret if ret!=float('inf') else -1)