function calc(x, y, l ,r: int64): int64;
  var n, nx, ny: int64;
    n1,n2: int64;
  begin
     if l < x then l := x;
     if x > r then begin
       result := 0;
       exit;
      end;

    if ( x = 1 ) then begin
       result := (r - l + 1);
       exit;
    end;
     if x = y then begin
       result := ( r div x - ((l-1) div x) );
       exit;
     end;
   if y + 1 >= x + x then begin
      result := (r - l + 1);
      exit;
   end;


    n := (y - 2) div ( y - x ) + 1;
    while  (y * (n - 1) + 1 >= x * n) and (n > 0) do dec(n);

  if n * x  <= l then begin
     result := (r - l + 1);
     exit;
  end;
  result := 0;
  if n*x <= r then begin
     result := r - n*x + 1;
     r:=n*x - 1;
  end;


      nx := (l + y - 1) div y;
      if nx*x > r then begin
        result := result + 0;
        exit;
      end;
      ny := r div x;
      if ny * y < l then begin
         result := result +0;
         exit;
      end;
      if ( ny * x <= l ) and (ny*y >= r)then begin
        result := result +r - l + 1;
        exit;
      end;
      if ( nx * x <= l ) and (nx*y >= r)then begin
        result := result +r - l + 1;
        exit;
      end;

      if (ny * y < l ) and ( ny * x + x > r) then begin
       result := result +(0);
       exit;
     end;
    if nx = ny then begin
       if l < nx * x then l := nx * x;
       if r > nx * y then r := ny * y;
       result := result +(r - l + 1);
       exit;
     end;

     if l < nx * x then l := nx * x;
     if r > nx * y then r := ny * y;

     n1 := nx + 1;
     n2 := ny - 1;
     if n1 <= n2 then
         result := result + (n2 - n1 + 1) + (y-x) * (( n1+n2) * (n2-n1+1) div 2);
     result := result + nx * y - l + 1  + (r - ny*x + 1);


  end;