from math import isqrt

N, K = map(int, input().split())

def solve(N, K):
	
	def isgood(x):
		for d in range(1, isqrt(x)+1):
			if x%d: continue
			if d <= K and x/d <= K:
				return False
		return True
	
	for x in range(N, max(0, N-300), -1):
		if isgood(x):
			return x
	return -1

print(solve(N, K))
ans = 0
for _ in range(9):
	z = solve(N, K)
	ans += z