Goto does not work in Pascal - why?

Question

Pascal

Continuing to write the program:
Program ferma;
var a: integer;
label 1, 2;
begin
a:=187;
1: if a=1 then goto 2;
if not Odd(a) then write (a/2) else write (a*3+1);
goto 1;
2: write(a);
end.
In response, it gives an infinite number of 562 - which is the reason for the question, because, since there is goto 1 below, it must repeat the condition of line 6, that is, divide 562 by 2. Why is this, what is connected with and what to do?

Answer 1

And where do you change the contents of the variable a?

Answer 2

since there is goto 1 at the bottom, it must repeat the condition of line 6, that is, divide 562 by 2

firstly, not 562 by 2, but the value of the variable a, that is, 187 by 2
; secondly, well, divide so what? variable will not change its value

what to do?

to start write what you want to get in the end