arctan1.pas

arctan.zip

program Arctan;

  const
    finp        = 'arctan.in';
    fout        = 'arctan.out';

  var
    a , b , u , y : comp;
    x : longint;

  begin
    assign(input , finp);
    reset(input);
    readln(a);
    close(input);
    b := a * a + 1;
    u := 1e13;
    for x := 1 to trunc(sqrt(b)) do begin
      y := int(b / x);
      if b = y * x then
        if x + y < u then u := x + y;
    end;
    u := u + 2 * a;
    assign(output , fout);
    rewrite(output);
    writeln(u : 0 : 0);
    close(output);
  end.