program x_y;
uses crt;
var a,b,c,d,x,y,mc:integer;
begin
clrscr;
write('Nhap a: '); readln(a);
write('Nhap b: '); readln(b);
write('Nhap c: '); readln(c);
write('Nhap d: '); readln(d);
mc:=b*d;
x:=b, y:=d;
while x<>y do
if x>y then x:=x-y else y:=y-x;
mc:=mc div x;
x:=a*(mc div b)+c*(mc div d);
y:=mc;
a:=x; b:=y;
while a<>b do
if a>b then a:=a-b else b:=b-a;
x:=x div a; y:=y div a;
write('x= ',x,' va y= ',y);
readln;
end.