Prog. Langs (Pascal) 1

Program HelloWorld(output);
var
    a, b, c:integer;

procedure PSwap(x, y:pointer) forward; // Defines prototype

procedure PSwap(x, y:pointer);
var z:integer;
begin
    z := integer(x^);
    integer(x^) := integer(y^);
    integer(y^) := z;
end;

function FAdd(var a, b:integer):integer;
begin
    FAdd := a + b;
end;

function FFact(n:integer):integer;
begin
    if n <= 1 then
        FFact := n
    else
        FFact := n * FFact(n-1);
end;

begin
    readln(a);
    readln(b);

    c := FFact(a);
    writeln(c);

    PSwap(@a, @b);
    writeln(a);
    writeln(b);
end.