Competitions

Function - 3

Implement a function f(x, y) = x2 + sin(x * y) - y2.

Input

Each line contains two real numbers x and y.

Output

For each test case print in a separate line the value of the function f(x, y) with four digits after the decimal point.

Time limit 1 second
Memory limit 128 MiB
Input example #1
2.234 2.12
10 23
56.1 0.012
23.26 5.1

Output example #1
-0.5034
-429.6161
3147.8333
514.3327

Author Mykhailo Medvediev
Source Programming language C