def is_prime(N):
    for i in range(2, N):
        if N % i == 0:
            return False
    return True

L, H = map(int, input().split())

nums = [i for i in range(L,H+1)]

for n in nums:
    if is_prime(n):
        nums.remove(n)

for i in range(2, H):
    j = 0
    while len(nums) > j:
        if len(nums) == 1:
            ans = nums[j]
        if nums[j] % i == 0:
            nums.pop(j)
            continue
        j = j + 1

print(ans)