Lunch

prb1289 Vlad wants to take along for lunch a couple of fruits. He has a banana A, B and C of apples pears. In how many ways he can choose 2 different types of fruit available to him?

Specifications

Input

In a single line through the space given three non-negative numbers: A, B and C. All the numbers do not exceed 10⁶.

Output

Single number - the answer to the problem.

Problem information

Time Limit: 0.1 seconds
Memory Limit: 64 MB
Balls for the passed test: 5
Complexity: 15% 300/351
Classes: Combinatorics

Example

Example input

3 4 2

Example output

← N-digit numbers

Problems

License plate →