Unclassified (maths): JEE Advanced 2020 Mathematics question

Suppose $a, b$ denote the distinct real roots of the quadratic polynomial $x^{2}+20 x-2020$ and suppose $c, d$ denote the distinct complex roots of the quadratic polynomial $x^{2}-20 x+2020$. Then the value of \[ a c(a-c)+a d(a-d)+b c(b-c)+b d(b-d) \] is