Natasha travel Mars Mars rover but suddenly break logical scheme inside the scheme undirected tree connect acyclic graph root vertex 1 leaf exclude root input vertex logical element include root output one bit fed input one bit return outputthere type logical element and 2 input or 2 input XOR 2 input not 1 input logical element value direct descendant input return result function perform Natasha know logical scheme Mars rover fact input break in order fix Mars rover need change value inputfor input determine output Natasha change input