if 2 erase s [ i ] and replace next with 7
if ( s [ i ] <= '2' ) : NEW_LINE INDENT s . pop ( i ) NEW_LINE s [ i ] = '7' NEW_LINE DEDENT elif ( s [ i ] == '3' ) : NEW_LINE INDENT s [ i ] = '2' NEW_LINE DEDENT elif ( s [ i ] <= '5' ) : NEW_LINE INDENT s [ i ] = '3' NEW_LINE DEDENT elif ( s [ i ] <= '7' ) : NEW_LINE INDENT s [ i ] = '5' NEW_LINE DEDENT else : NEW_LINE INDENT s [ i ] = '7' NEW_LINE DEDENT def primeDigits ( s ) : NEW_LINE s = [ i for i in s ] NEW_LINE i = 0 NEW_LINE while i < len ( s ) : NEW_LINE