# Lunch

Very easy

Execution time limit is 1 second

Runtime memory usage limit is 128 megabytes

Vlad wants to take a couple of fruits for lunch. He has $a$ different bananas, $b$ different apples and $c$ different pears. In how many ways can he choose $2$ different fruits from the available ones?

## Input

Three non-negative integers $a,b$ and $c$ are given. All integers do not exceed $10_{6}$.

## Output

Print the number of ways to choose $2$ different fruits for lunch.

## Examples

Input #1

Answer #1

Submissions 13K

Acceptance rate 50%