MathDB

The

49

numbers

2,3,4,...,49,50

are written on the blackboard . An allowed operation consists of choosing two different numbers

a

and

b

of the blackboard such that

a

is a multiple of

b

and delete exactly one of the two. María performs a sequence of permitted operations until she observes that it is no longer possible to perform any more. Determine the minimum number of numbers that can remain on the board at that moment.

Problem Statement