PROGRAMMING:Xiao Ming's new operation
Addition, subtraction, multiplication and division are the most basic four operations in primary school mathematics. Now Xiao Ming has defined a new operation based on this. The operator is "△", and the operation rule is: a △ B = a × b ×( b+1) ÷ 2。
For example: 5 △ 3 = 5 × three ×( 3+1) ÷ 2=30。
Presumably such a problem will not be difficult for you, please program and output the result of a △ B.
###Input format:
There is only one line, two integers a and B separated by spaces.
###Output format:
And there's only one line for a △ B.
###Input example:
```in
5 3
```
###Output example:
```out
thirty
```
[data range]
0 ≤ a, B ≤ 10000, a and B and the result of operation are integers< br>
answer：If there is no answer, please comment
For example: 5 △ 3 = 5 × three ×( 3+1) ÷ 2=30。
Presumably such a problem will not be difficult for you, please program and output the result of a △ B.
###Input format:
There is only one line, two integers a and B separated by spaces.
###Output format:
And there's only one line for a △ B.
###Input example:
```in
5 3
```
###Output example:
```out
thirty
```
[data range]
0 ≤ a, B ≤ 10000, a and B and the result of operation are integers< br>
answer：If there is no answer, please comment