一道ACM题，有兴趣的来看看

A fracion a/b(a < b) can be expressed in the way 1/b1 + 1/b2 + ... + 1/bn. Now can you achieve it and make the sum of b1 to bn minimum?

（一个分数可以表示成1/b1+...+1/bn.现在让你求一个这样的序列使得bi之和最小）

Input and Output

For each case there are tow positive intergers a and b( 0 < a < b <= 100), output the minimum sum.

Sample Input

2 3

3 4

4 15

Sample Output

6

6

16

Hint: 2/3 = 1/3 + 1/3, 4/15 = 1/6 + 1/10

[391 byte] By [msdn] at [2007-8-14 20:04:55]