PROGRAMMING:Floor tile
Garden is the richest man in the world. On Christmas Eve, he bought a villa and prepared to send it to the first person with the title of "a". The title is like this: Garden Villa has a floor with a length of N and a width of M. he is going to put some "a" in it × How many dominoes can I put at most?
###Input format:
Enter two integers n and m, which means the length is n and the width is m (1 < = n, m < = 100)
###Output format:
Output an integer, that can put up to how many pieces of domino
###Input example:
Here is a set of inputs. For example:
```in
1 2
```
###Output example:
The corresponding output is given here. For example:
```out
one
```
answer：If there is no answer, please comment
###Input format:
Enter two integers n and m, which means the length is n and the width is m (1 < = n, m < = 100)
###Output format:
Output an integer, that can put up to how many pieces of domino
###Input example:
Here is a set of inputs. For example:
```in
1 2
```
###Output example:
The corresponding output is given here. For example:
```out
one
```
answer：If there is no answer, please comment