现在，给出正方形的边长n，以及需要封地的诸侯数量k，要求你求出所有可能的安置方案数。(n≤l00，k≤2n2-2n+1)。由于方案数可能很多，你只需要输出方案数除以504的余数即可。

【输入】

仅一行，两个整数n和k，中间用一空格隔开。

【输出】

一个整数，表示方案数除以504的余数。

【样例输入】

2 2

【样例输出】

4

-Now, give a square of side length n, as well as the quantity required feudal fief of the k, find all ask you to program the number of possible resettlement. (n ≤ l00, k ≤ 2n2-2n+1). Probably a lot of programs because of the number, you only need to program the number of output divided by the remainder of 504 can. 【Input】 only his party, the two integers n and k, with a space between separated. 【Output】 an integer, said the program divided by the remainder of 504. Sample input 2】 【2】 【sample output 4