$$(2345678+3456782+4567823+5678234+6782345+7823456+8234567)\div5$$=~\uline{~~~~~~~~~~}~ 
Overseas Competition->Knowledge Point->Number Theory Modules->Place Value and Number Bases->Applying the Principle of Place Value
$$(2+3+4+5+6+7+8)\times1111111\div5$$  $$=7777777 