def ascan; gets.split.map(&:to_i);end

require 'prime'

L, H = ascan

sqrtH = Math.sqrt(H).to_i

ans = [0,0]

sqrtH.downto(2) do |x|
    next unless x.prime? ## 篩を使えばこの計算量をループの外に出せる
    y = H / x
    yfact =  y.prime_division.map(&:shift).min ## niceな実装ならO(sqrt(N))
    next if x * y < L
    
    curr = [ [x,yfact].min, x*y ]
    ans = [curr, ans].max
end

p ans[1]