program hoan_doi;
ues crt;
var
A,B: byte;
begin
clrscr;
write('Nhap gia tri A= ');
readln(A);
write('Nhap gia tri B= ');
readln(B);
writeln('Gia tri ban dau: A= ',A,'; B=',B);
A:= A + B;
B:= A - B;
A:= A - B;
writeln('Gia tri sau khi hoan chuyen: A= ',A,'; B=',B);
readln
end.