human
Largest sub | Function to return the largest substring divisible by 2.
While the last character of the string is '1' , pop it.
If the original string had no '0.
Driver code"
Solution in Python:
assistant
#Here is code to largest sub and the other steps required.
 def largestSubStr ( s ) :
	while ( len ( s ) and s [ len ( s ) - 1 ] == '1' ) :
		s = s [ : len ( s ) - 1 ] ;
'
	if ( len ( s ) == 0 ) :
		return " - 1" ;
	else :
		return s ;
if __name__ == " _ _ main _ _ " :
	s = "11001" ;
	print ( largestSubStr ( s ) ) ;