Problem 4. (20 points) Trace the execution of the following algorithm on input a-87,b 93. That is, show all steps it uses to compute ged(87, 93) Procedure GCD(a, bINTEGERS WITH a, b 20) 1 ifb 0 then 2return a a return ged(b, a mod b) I/ output is greatest common divisor of a and b