with return push 1000 visit 1000 visit 1001 return 1001 visit 1002 return 1002 visit 1003 return 1003 return 1000 push 1100 visit 1100 visit 1101 visit 1102 return 1102 return 1101 visit 1102 visit 1103 return 1103 return 1100 push 2000 visit 2000 visit 2001 return 2001 visit 2002 visit 2004 visit 2005 visit 2006 return 2006 visit 2007 return 2007 visit 2008 return 2008 return 2005 return 2004 return 2002 visit 2003 return 2003 return 2000 just visit push 1000 visit 1000 visit 1001 visit 1002 visit 1003 push 1100 visit 1100 visit 1101 visit 1102 visit 1102 visit 1103 push 2000 visit 2000 visit 2001 visit 2002 visit 2004 visit 2005 visit 2006 visit 2007 visit 2008 visit 2003