Wrote on Pascal:

var
  i, j: integer;
  ms, a, b: integer;
  arrg: array of integer;
begin
  Read(ms);
  SetLength(arrg, ms);

  for i := 0 to arrg.Length - 1 do begin
    var temp: integer;
    Read(temp);
    arrg[i] := temp;
  end;

  for j := 1 to arrg.Length - 1 do
    for i := 1 to arrg.Length - j do
      if arrg[i - 1] > arrg[i] then
        Swap(arrg[i - 1], arrg[i]);

  a := arrg.Length div 2;

  for i := 0 to a do
    b := b + arrg[i] div 2 + 1;

  Write(b);
end.

Wrong answer ( test 1 ).

arrg.Length it may be odd