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Regular expressions are composed of literal characters and ___. Literal characters are those that match exactly with the same characters in the input text. Metacharacters, on the other hand, have special meanings and are used to create more complex patterns.

Here are some examples of metacharacters:

• . (dot): Matches any character except a newline.
• * (asterisk): Matches zero or more occurrences of the preceding character or group.
• + (plus): Matches one or more occurrences of the preceding character or group.
• ? (question mark): Matches zero or one occurrence of the preceding character or group.
• [] (square brackets): Matches any single character within the brackets.
• () (parentheses): Groups multiple characters together.