Step 1: read in the values of X and Y.

Step 2: subtract Y from X.
Step 3. If the difference between the X and Y
is negative, compute R=X+Y; if zero, compute
r=2x+2y; and if positive, compute R=X*Y.

read x,y

z = x-y
v = (x<y) ? x+y : (x>y) ? x*y : 2x+2y