"elem1"	"elem1-1"
"elem2"	"elem2-1"
"elem2"	"elem2-2"
"elem3"	"elem3-1"
"elem3"	"elem3-2"
"elem3"	"elem3-3"
"elem4"	"elem4-1"
"elem4"	"elem4-2"
"elem4"	"elem4-3"
"elem4"	"elem4-4"