407042: GYM102697 013 Resistors in Parallel

When two resistors with resistances a and b are parallel in an electronic circuit, their equivalent resistance is calculated as (a * b) / (a + b). Given the resistances of two resistors, calculate their equivalent resistance.

The first line of input contains a single positive integer a: the resistance of the first resistor. The second line of input contains a single positive integer b: the resistance of the second resistor.

Output a single positive decimal number r: the equivalent resistance of the two resistors, calculated using the above formula.

60
40

24.0

80
70

37.333333333333336