What is the value of X printed by the following program?

program COMPUTE (input, output);
var
    X:integer;
procedure FIND (X:real);
    begin
    X:=sqrt(X);
    end;
begin
   X:=2
   Find(X)
   Writeln(X)
end

What does the following code do?

var a, b : integer;
begin
    a:=a+b;
    b:=a-b;
    a:=a-b;
end;