Define a function calc$\_$val$()$ that has two parameters and returns the result of subtracting the product of $8\mathrm{.}7$ and the second parameter from the first parameter.

Ex: If the input is:

$6\mathrm{.}3$

$6\mathrm{.}4$

then the output is:

$-49\mathrm{.}38$

def calc$\_$val$($parameter$)$:

parameter $-8\mathrm{.}71$

num$\_$read$1=$ float input $()$