Largest Prime Factor

Given a positive integer \(n\), your task is to compute its largest prime factor. The largest prime factor is the largest prime number that divides \(n\) exactly.

Note: When the number is prime, its largest prime factor is the number itself.

For example, if \(n = 15\), its prime factors are 3 and 5, and the largest is 5.

inputFormat

The input consists of a single line that contains a positive integer \(n\) (\(2 \le n \le 10^{15}\)). The input is provided via stdin.

outputFormat

Output the largest prime factor of \(n\) to stdout.

15

5