# num = int(input('请输入一个是十进制数：'))
# lst = []
# while num != 0:
#     a = num % 16
#     if 0 <= a <= 9:
#         lst.append(a)
#     elif 10 <= a <= 15:
#         lst.append(chr(87 + a))
#     else:
#         print('数据有误')
#     num //= 16
# for i in range(len(lst) - 1, -1, -1):
#     print(lst[i], end='')

print(8**-1)