URL Shortener

You are given the task to implement a URL Shortener service. The service converts a long URL into a short, unique code and also retrieves the original URL when provided with the short code. The same long URL should always get the same short code. Internally, you may use a counter and convert it to a base-62 representation, where the conversion formula is given by $$\text{short\_code} = \text{base62}(\text{counter})$$ with $$\text{base} = 62$$ and the character set defined as all lowercase letters, uppercase letters, and digits.

The program will process a series of operations. Each operation is one of the following:

• Encode Operation: Given a long URL, convert it to a short URL. (Input prefix "1")
• Decode Operation: Given a short URL, return the original long URL. If it does not exist, output an empty string. (Input prefix "2")

All input is received from standard input and output must be sent to standard output.

inputFormat

The first line contains an integer N representing the number of operations. Each of the following N lines contains an operation:

1. If the line starts with 1 followed by a space and a URL, you need to encode the long URL.
2. If the line starts with 2 followed by a space and a short URL, you need to decode it.

Note: The URLs can be any string including the empty string.

outputFormat

For each operation, output the result on a new line. For an encode operation, output the generated short URL. For a decode operation, output the corresponding long URL (or an empty string if not found).

## sample

7
1 https://www.example.com/articles/how-to-code-in-python
1 https://www.example.com/articles/learn-java
1 https://www.example.com/articles/learn-cpp
1 https://www.example.com/articles/how-to-code-in-python
2 b
2 c
2 e

b
c
d
b
https://www.example.com/articles/how-to-code-in-python
https://www.example.com/articles/learn-java

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