notam:
a=a
b=a+1
c=a+1+1
d=a+1+1+1
e=a-28
a =[-------]+28
a+1 =[-------]+1+28
a+1+1 =[-------]+1+1+28
a+1+1+1=[-------]+1+1+1+28
e =[-------]
e= (318 -1*6 - 28*4)/5
e= (318 - 6 - 112)/5
e= (312 - 112)/5
e=200/5=40
a= 40+28=68
a+1=68+1=69
a+1+1=69+1=70
a+1+1+1=70+1=71
R:a=68
b=69
c=70
d=71
e=40