#5 Two factors

Which the least number n can we imagine in product n = a∙b like k ways? Products a∙b and b∙a is one of the way, where all numbers is natural (1≤ k ≤50).

Specifications

Input

One number k.

Output

One number n.

Time Limit: 1 seconds
Balls for the passed test: 7.69231
Complexity: 74%

Example

Example input

2

Example output

4

Problem URL: http://www.e-olimp.com.ua/en/problems/5