codeforces#P72C. Extraordinarily Nice Numbers
Extraordinarily Nice Numbers
Description
The positive integer a is a divisor of the positive integer b if and only if there exists a positive integer c such that a × c = b.
King Astyages thinks a positive integer x is extraordinarily nice if the number of its even divisors is equal to the number of its odd divisors.
For example 3 has two positive divisors 3 and 1, both of which are odd, so 3 is not extraordinarily nice. On the other hand 2 is only divisible by 2 and 1, so it has one odd and one even divisor. Therefore 2 is extraordinarily nice.
Given a positive integer x determine whether it's extraordinarily nice.
The input contains only a single integer x (1 ≤ x ≤ 103).
Write a single yes or no. Write yes if the number is extraordinarily nice and no otherwise.
You don't need to care about capital or small letters. The output is case-insensitive.
Input
The input contains only a single integer x (1 ≤ x ≤ 103).
Output
Write a single yes or no. Write yes if the number is extraordinarily nice and no otherwise.
You don't need to care about capital or small letters. The output is case-insensitive.
Samples
2
yes
3
no