program swap;
var a,b,c:integer;
begin
a:=8;
b:=13;
a:=a+b;
b:=a-b;
a:=a-b;
writeln ('a=', a);
writeln ('b=', b);
end.
program swap;
var a, b, c: integer;
begin
a := 8;
b := 13;
a := a + b;
b := a - b;
a := a - b;
writeln('a=', a);
writeln('b=', b);
end.