A. Almost Primetime limit per test2 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outputA number is called almost prime if it has exactly two distinct prime divisors. For example, numbers 6, 18, 24 are almost prime, while 4, 8, 9, 42 are not. Find the amount of almost prime numbers which are between 1 and n, inclusive.InputInput contains one integer number n (1 ≤ n ≤ 3000).OutputOutput the amount of almost prime numbers between 1 and n, inclusive.ExamplesInput10Output2Input21Output8
Input10
Output2
['number theory', '*900']