Cupcakes#1996
After the Olympics, the satisfied but hungry programmers went to the nearest café and ordered cupcakes.
The cupcake preparation process involves baking the cupcake dough for two minutes and the icing for one minute. To achieve this, the chef first places the cupcake in the oven for one minute without icing. After this, the cupcake is removed, the icing is applied, and it is returned to the oven for another minute. At this point, the cupcake is ready. During the second minute, both the dough and the icing bake; this is the first (and only necessary) minute for the icing and the second minute for the dough. The process allows for a pause between these two stages but does not permit splitting the baking minute into smaller parts. Some cupcakes can be baked with icing while others are without icing at the same time.
The chef's oven can accommodate cupcakes at once. Determine how many minutes the chef will need to complete the programmers' order.
The input consists of a single line containing two integers and (1 \leq N, K \leq 1000) — representing the number of cupcakes and the oven's capacity, respectively.
Output a single number — the minimum number of minutes the chef will need to prepare cupcakes.
Example 1