Contest Duration: - (local time) (100 minutes) Back to Home
A - Apple Pie /

Time Limit: 2 sec / Memory Limit: 1024 MB

### 制約

• 入力は全て整数である。
• 0 \leq A, P \leq 100

### 入力

A P


### 入力例 1

1 3


### 出力例 1

3


3 つある林檎の欠片のうち 2 つを鍋で煮込むことで、まず 1 つのアップルパイを作ることができます。林檎の欠片が 1 つ残りますが、これと、1 つある林檎を砕いて新しく得た 3 つの林檎の欠片から、さらに 2 つのアップルパイを作れます。

### 入力例 2

0 1


### 出力例 2

0


### 入力例 3

32 21


### 出力例 3

58


Score : 100 points

### Problem Statement

We have A apples and P pieces of apple.

We can cut an apple into three pieces of apple, and make one apple pie by simmering two pieces of apple in a pan.

Find the maximum number of apple pies we can make with what we have now.

### Constraints

• All values in input are integers.
• 0 \leq A, P \leq 100

### Input

Input is given from Standard Input in the following format:

A P


### Output

Print the maximum number of apple pies we can make with what we have.

### Sample Input 1

1 3


### Sample Output 1

3


We can first make one apple pie by simmering two of the three pieces of apple. Then, we can make two more by simmering the remaining piece and three more pieces obtained by cutting the whole apple.

### Sample Input 2

0 1


### Sample Output 2

0


We cannot make an apple pie in this case, unfortunately.

### Sample Input 3

32 21


### Sample Output 3

58