require 'prime'

l,h=gets.split(" ").map(&:to_i)

ansval=nil #暫定の最小の素因数
answer=0   #暫定の解

Math::sqrt(h).to_i.downto(2){|j|

    next  if h/j*j<l
    next  if !Prime.prime?(j)
    break if ansval!=nil && j<ansval
    
    (h/j).downto(j){|i|
    	break if i*j<l
    	t=Prime.prime_division(i*j)[0][0]
        if (ansval==nil || ansval<t || (ansval==t && answer<i*j))
    	    ansval=t
    	    answer=i*j
    	end
    }
}
p answer