Score: 300 points
Find the minimum prime number greater than or equal to X.
A prime number is an integer greater than 1 that cannot be evenly divided by any positive integer except 1 and itself.
For example, 2, 3, and 5 are prime numbers, while 4 and 6 are not.
Input is given from Standard Input in the following format:
X
Print the minimum prime number greater than or equal to X.
20
23
The minimum prime number greater than or equal to 20 is 23.
2
2
X itself can be a prime number.
99992
100003