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We are given a set of positive integers. We would like to find a subset of , composed of as few elements as possible, such that the only positive common divisor of all the elements of is 1.

The first line of input contains one integer (), the size of the set . The second line contains a sequence of positive integers () that represents the elements of the set .

The only line of output should contain one integer: the size of the requested smallest
set or a single word `BRAK` (Polish for *none*) if the set does not exist.

For the input data:

5 6 10 12 15 18

the correct result is:

3

whereas for the input data:

5 2 4 6 8 10

the correct result is:

BRAK

*Task author: Jakub Lacki.*