Garage

1000ms

131072K

Description:

Pak Chanek plans to build a garage. He wants the garage to consist of a square and a right triangle that are arranged like the following illustration.

$\text{[math]}$

Define $$$a$$$ and $$$b$$$ as the lengths of two of the sides in the right triangle as shown in the illustration. An integer $$$x$$$ is suitable if and only if we can construct a garage with assigning positive integer values for the lengths $$$a$$$ and $$$b$$$ ($$$a<b$$$) so that the area of the square at the bottom is exactly $$$x$$$. As a good friend of Pak Chanek, you are asked to help him find the $$$N$$$-th smallest suitable number.

Input:

The only line contains a single integer $$$N$$$ ($$$1 \leq N \leq 10^9$$$).

Output:

An integer that represents the $$$N$$$-th smallest suitable number.

Sample Input:

Sample Output:

Note:

The $$$3$$$-rd smallest suitable number is $$$7$$$. A square area of $$$7$$$ can be obtained by assigning $$$a=3$$$ and $$$b=4$$$.

Informação

Provedor Codeforces

Código CF1725G