CSES - HIIT Open 2019 - Alien Invasion II
  • Time limit: 1.00 s
  • Memory limit: 512 MB

The aliens are coming and there is only one way to stop them: you have to solve a difficult mathematical problem.

The aliens give you an integer, and you have to add some digits to the front of the number so that the resulting number is not a prime.


The only input line has a positive integer that consists of at most 30 digits.


First print a new integer x that is not a prime. You may add 0 \dots 5 digits.

Then, show why your integer is not prime by giving two more integers a and b such that 1 < a,b < x and a \cdot b = x.





41 137

Explanation: You add two digits and create the number 5617 which is not prime because 41 \cdot 137 = 5617.