A prime number is an integer greater than 1 that has no positive divisors other than 1 and itself. The first prime numbers are 2, 3, 5, 7, 11, 13, 17, ...
The number N is considered far from primes if there are no prime numbers between N-10 and N+10, inclusive, i.e., all numbers N-10, N-9, ..., N-1, N, N+1, ..., N+9, N+10 are not prime.
You are given an int A and an int B. Return the number of far from primes numbers between A and B, inclusive.
|-||A will be between 10 and 100000, inclusive.|
|-||B will be between A and 100000, inclusive.|
|-||(B - A) will be between 0 and 1000, inclusive.|