Mock CCC '20 Contest 1 J5 - A Prime Problem

Points: 12 (partial)

Time limit: 0.5s

Memory limit: 1G

Problem type

koosaga likes numbers which are constructed by concatenating two prime numbers together. A number which can be formed by concatenating two primes that both have at least $D$ ~D~ digits is a $D$ ~D~-level prime pair certificate. Leading zeroes are not permitted.

Given two integers $D$ ~D~ and $N$ ~N~, compute the smallest $D$ ~D~-level prime pair certificate greater than or equal to $N$ ~N~.

Constraints

The output will never exceed $2 \cdot 10^9$ ~2 \cdot 10^9~.

There are no subtasks for this problem.

Input Specification

The input will consist of two positive space separated integers, $D$ ~D~ and $N$ ~N~.

Output Specification

Output the smallest $D$ ~D~-level prime pair certificate greater than or equal to $N$ ~N~.

Sample Input

2 11328

Sample Output

Comments

-4

Togohogo1 commented on Feb. 29, 2020, 7:42 p.m. ← edit 3 →

Does N or D in the input have leading zeros?

I'm just wondering because I got WA on test case #642. It's probably because there is something else wrong with my program.

Edit: Fixed the error