循环小数的求解得到的概率问题的算法，运用C语言的程序的设计的方式如何实现

Problem Description
LL is very lazy. Recently, he is assigned to a dormitory in the 5th floor and sometimes it's hard for him to decide whether to step out for some snack at night. So he choose two positive integers x, y and decide to go or not to go by the low bit of x (l is the length of x in binary representation). If it is "1", he choose to go and if it is "0", he stay in the dormitory.

Input
Each line contain two positive integers a and b (both not larger than 10^7 and a<=b). x is randomly chosen from [a,b]. No limit on y.

Output
For each case, output the probability (accurate to 6 fractional digits) of getting "1".

Sample Input
1 1
3 5

Sample Output
1.000000
0.666667