in the mathematical circle, they study the Goldbach hypothesis, which claims that any even number of two simple numbers can be presented. Your task & mdash; Find all the possible ways to represent a given even number in the form of the sum of two simple numbers.
rn
for each even number you need to find all pairs of simple numbers that give this number in total. The couples should be streamlined by an increase in the first element, and inside each pair the first number should be no more than the second.
Input format
one even number n (4 & le; n & le; 100)
Output format
all pairs of simple numbers, the sum of which is equal to n. Each pair is displayed in a separate line in the format "A B", where a & le; B. Couples are streamlined by an increase in the first element
Hint
There will be no clue here, decide for yourself!