Appendable Substrings

You are given a string \(S\). Determine if \(S\) can be constructed by starting with an empty string and repeatedly appending any one of the following substrings:

• apple
• banana
• 321
• xyz

You may use each substring any number of times (including zero). Output YES if it is possible to construct the string exactly, otherwise output NO.

Note: The empty string is considered valid and should output YES.

inputFormat

The input consists of a single line that contains the string \(S\) (which may be empty). \(S\) will only contain alphanumeric characters.

outputFormat

Output a single line with YES if the string can be formed by concatenating one or more of the allowed substrings; otherwise, output NO.

321applebanana

YES