If "101" matches the sub - string starting at current index i
elif ( s [ i ] == '1' and s [ i + 1 ] == '0' and s [ i + 2 ] == '1' ) : NEW_LINE INDENT count += 1 ; NEW_LINE i += 3 ; NEW_LINE DEDENT else : NEW_LINE INDENT i += 1 ; NEW_LINE DEDENT return count ; NEW_LINE