program hoan_doi;
var x,y,z : integer;
begin
read(x,y);
writeln(x,'',y) ;
z := x;
x:=y ;
y:= z ;
writeln (x,'',y) ;
readln
end.
Mình ko chắc
var a,b,c:integer;
begin
write('a=');readln(a);
write('b=');readln(b);
c:=a;
a:=b;
b:=c;
writeln('ket qua: ',a,' va ',b);
readln;
end.