Ветвящиеся алгоритмы

function s(x1:integer; y1:integer; x2:integer; y2:integer; x3:integer; y3:integer) : real;
var
l1,l2,l3,p : real;
begin
l1:=sqrt(sqr(x1-x2)+sqr(y1-y2));
l2:=sqrt(sqr(x2-x3)+sqr(y2-y3));
l3:=sqrt(sqr(x1-x3)+sqr(y1-y3));
p:=(l1+l2+l3)/2;
s:=sqrt(p*(p-l1)*(p-l2)*(p-l3));
end;
var
su,sun,sunn,suu : real;
x,y : integer;
begin
writeln('Enter the coordinates:');
readln(x);
readln(y);
su:=0;
su:=su+s(4,4,3,8,5,7);
su:=su+s(4,4,3,8,0,5);
su:=su+s(4,4,7,3,5,7);
su:=su+s(4,4,7,3,6,0);
su:=su+s(4,4,5,0,6,0);
su:=su+s(4,4,0,5,5,0);
sun:=0;
sun:=sun+s(x,y,3,8,5,7);
sun:=sun+s(x,y,3,8,0,5);
sun:=sun+s(x,y,7,3,5,7);
sun:=sun+s(x,y,7,3,6,0);
sun:=sun+s(x,y,5,0,6,0);
sun:=sun+s(x,y,0,5,5,0);
writeln(sun);
writeln(su);
if abs(sun-su)<0.00000001 then writeln('Yep')
          else writeln('Nope');
readln;
end.

uses crt;
var x,y:real;
 
begin
 clrscr;
 write('X Y-> ');
 readln(x,y);
 if (y>-x+5) and (y<x+5) and (y<-0.5*x+9.5) and (y<-2*x+17) and (y>x*3-18) and (y>0) then write('YES') else write('NO');
 readln;
end.