func main()
	var ss: [][]char :: cui@input().split(" ")
	var N: int :: ss[0].toInt(&)
	var K: int :: ss[1].toInt(&)
	var primes: []int :: math@primeFactors(N)
	var min: int :: 1
	for i(0, K - 1)
		do min :* primes[i]
	end for
	
	var maxDivisorNum: int :: getDivisorNum(math@primeFactors(min))
	var ans: int :: min
	for n(min, N - 1)
		var primes2: []int :: math@primeFactors(n)
		var divisorNum: int :: getDivisorNum(primes2)
		if(divisorNum > maxDivisorNum)
			if(commonDevisorNum(primes, primes2) >= K)
				do maxDivisorNum :: divisorNum
				do ans :: n
			end if
		end if
	end for
	do cui@print("\{ans}\n")
	
	func commonDevisorNum(primes1: []int, primes2: []int): int
		var i1: int :: 0
		var i2: int :: 0
		var res: int :: 0
		while(true)
			if(i1 >= ^primes1)
				ret res
			end if
			if(i2 >= ^primes2)
				ret res
			end if
			if(primes1[i1] = primes2[i2])
				do res :+ 1
				do i1 :+ 1
				do i2 :+ 1
			elif(primes1[i1] < primes2[i2])
				do i1 :+ 1
			else
				do i2 :+ 1
			end if
		end while
	end func
	
	func getDivisorNum(primes: []int): int
		var res: int :: 1
		var lastNum: int :: 0
		var num: int :: 1
		for i(0, ^primes - 1)
			if(primes[i] = lastNum)
				do num :+ 1
			else
				do res :* num
				do num :: 2
			end if
			do lastNum :: primes[i]
		end for
		do res :* num
		ret res
	end func
end func