Hello, I try to solve a adventofcode challenge where I must find out when santa is first at the basement. the floor is there -1. So I thought I use a while loop like this : santaFloorOnBasement    "calculates which step take Santa to the basement"     | index|     index := 1.     ??? when: (floor >=0 ) do:        [ floor := (input at: index = '(' )                ifTrue: [ floor + 1 ]                ifFalse: [ floor - 1 ].         index := index + 1 ]. but I cannot find out what must be instead of the ?? index is the index of the string which has to start with a 1. floor and input are both instance variables. floor contains the current floor and input the input of the challenge. Can someone help me figure this out so the next time I can do this on my own. Roelof