sort all the numbers
sort ( oneTwoThree . begin ( ) , oneTwoThree . end ( ) ) ; string result = " " ; for ( auto number : oneTwoThree ) { int value = number ; if ( result . length ( ) > 0 ) result += " , ▁ " ; result += to_string ( value ) ; } return ( result . length ( ) > 0 ) ? result : " - 1" ; }