uses crt;

var a,b,ta,te,kq:longint;

begin

clrscr;

repeat

write('Nhap tuoi cua anh='); readln(a);

write('Nhap tuoi cua em='); readln(b);

until (a>0) and (b>0) and (a>b);

ta:=a*2;

te:=b*2;

kq:=ta-te;

if a-kq>0 then writeln('Truoc ',a-kq,' nam')

else if a-kq<0 then writeln('Sau ',kq-a,' nam')

else writeln('Hien tai tuoi cua anh gap doi tuoi cua em');

readln;

end.

Vote 5* vs đảm bảo đúng

uses crt;
var y,x,tuoianh,tuoiem,s:longint;
begin
clrscr;
repeat
write('Nhap tuoi cua anh='); readln(x);
write('Nhap tuoi cua em='); readln(y);
until (x>0) and (y>0) and (x>y);
tuoianh:=x*2;
tuoiem:=y*2;
s:=tuoianh-tuoiem;
if x-s>0 then writeln('Truoc ',x-s,' nam')
if a-kq<0 then writeln('Sau ',s-x,' nam')
else writeln('Hien tai tuoi cua anh gap doi tuoi cua em');
readln;
end.

HỌC TỐT !!!

~~~Dân cao thủ tin học~~~