Problems
Value of variable 2
Value of variable 2
Find the value of the variable $y$ for a given real value of the variable $x$.
$$
y = x - {x^2 + 4 \over 2} + x^3 - {3 \over x + 7}
$$
\InputFile
Value of the variable $x$.
\OutputFile
Print the value of the variable $y$ up to thousandths.
Input example #1
1
Output example #1
-0.875