a = 1 + 2
b = a + 3
c = a + b
return a + b + c

// Iteration 1
a = 3
b = 3 + 3
c = 3 + b
return 3 + b + c

// Iteration 2
a = 3
b = 6
c = 3 + 9
return 3 + 6 + c

// Iteration 3
a = 3
b = 6
c = 12
return 9 + 12

// Iteration 4 (With Dead Assignment Removal)
return 21