Fox Jiro likes dice. He wants to make his own dice. Each die he wants to make is a cube. Each of the 6 faces has an integer between 1 and N, inclusive. No two faces have same number. Also the following condition must be satisfied: for all faces, the sum of the numbers on opposite faces must be equal and the sum must be greater than or equal to K.
He realized that there are many ways to make such dice. He wants to know how many ways there are. Please help Jiro to make a program that is given two integers N and K and returns the number of different dice satisfying the condition mentioned above.
Two dice are considered the same if you can rotate one to form the other.