Primers Bessons P98817


Statement
 

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Twin prime numbers are pairs of prime numbers that differ by 2. That is, p and q (with p < q) are twin primes if p and q are primes and q = p + 2. Except for the case of 2 and 3, this is the smallest difference that can exist between two primes. The first examples of the list of twin primes are the pairs (3, 5), (5,7) and (11,13).

The term was first used by the German mathematician Paul Stäckel who, at the end of the 19th century, made some numerical calculations related to these numbers and other related questions. It is not known if there are infinite twin prime numbers. The twin prime conjecture that states that, in fact, there are infinite twin primes, has not yet been proven[Wikipedia].

Write a program that, given a natural number n>0, calculates the n-th pair of twin primes. For example, if n = 3, the program must calculate the twin primes 11 and 13.

Your program should define and use the nth_twin_primes(n: int) -> tuple[int, int] function, which returns the n-pair of twin numbers for an n ≥ 1. Your program should also define and use the are_primes(m: int, n: int) -> bool function, which tells if m and n are primer numbers, for m,n≥ 2.

Input

The input consist of a series of strictly positive integers n.

Output

For each n you must write a line with the two twin primes that form the pair, separated by a space. Each pair must be in increasing order.

Observation

As many pairs of numbers will be composite, it is not a good idea to determine if both are prime separately in the are_primes function.

Public test cases
  • Input

    3
    10
    54
    7
    99
    

    Output

    11 13
    107 109
    1697 1699
    59 61
    3767 3769
    
  • Information
    Author
    Jordi Puig
    Language
    English
    Translator
    Jordi Puig
    Original language
    Catalan
    Other languages
    Catalan
    Official solutions
    Python
    User solutions
    Python