An identifier is a sequence of characters. A valid identifier can contain only upper and lower case alphabetic characters, underscore and digits, and must begin with an alphabetic character or an underscore. Given a list of chararcter sequences, write a program to check if they are valid identifiers.
For each of the N lines, output "Yes" (without quote marks) if the character sequence contained in that line make a valid identifier; output "No" (without quote marks) otherwise.
7 ValidIdentifier valid_identifier valid_identifier 0 invalid identifier 1234567 invalid identifier adefhklmruvwxyz12356790 -.,:;!?'"()ABCDGIJLMQRSTVWXYZ
Yes Yes Yes No No No No