Competitions

# Азербайджан - подготовка. Март 12

# Triangle Counting

You are given **n** rods of length **1**, **2**, . . . , **n**. You have to pick any **3** of them and build a triangle. How many distinct triangles can you make? Note that, two triangles will be considered different if they have at least **1** pair of arms with different length.

#### Input

Each line has one positive integer **n** (**3** ≤ **n** ≤ `10`

). The end of input will be indicated by a case with ^{6}**n** < **3**. This case should not be processed.

#### Output

For each test case, print the number of distinct triangles you can make.

Input example #1

5 8 0

Output example #1

3 22