Competitions

# S.C.

# Combination

How many numbers are divisible by the prime number **p** in the first **n** rows of Pascal Triangle? In other words, find the number of pairs (**j**, **i**) (**0** ≤ **j** ≤ **i** < **n**) so that **C**(**i**, **j**) is divisible by **p**. Here

#### Input

The first line contains two integer numbers **n**, **p** (**1** ≤ **n** ≤ `10`

, ^{7}**3** ≤ **p** ≤ **100**).

#### Output

Print the answer.

Input example #1

5 3

Output example #1

3

Input example #2

100 7

Output example #2

2689