program massiv;

{$APPTYPE CONSOLE}

uses
  SysUtils;

var
  n, a, k, j, i, sum: integer;
begin
  k := 0;
  j := 0;
  sum := 0;
  readln (n);
  for i := 1 to n do begin
    readln (a);
    if (a mod 3 = 1) then begin
      inc (sum);
      inc (k);
    end;
    if (a mod 3 = 2) then begin
      inc (sum, 2);
      inc (j);
    end;
  end;
  if (sum mod 3 = 1) then
    if (k >= 1) then
      writeln (n - 1)
    else
      writeln (n - 2);
  if (sum mod 3 = 2) then
    if (j >= 1) then
      writeln (n - 1)
    else
      writeln (n - 2);
  if (sum mod 3 = 0) then
    writeln (n);
  readln;
  readln;
end.