Largest Time From Digits

You are given four digits. Your task is to arrange these digits to form the largest possible valid time in 24-hour format (HH:MM). If no valid time can be formed, output an empty string.

A valid time must satisfy the following conditions:

• The hour, denoted as \(HH\), must be between 00 and 23 inclusive.
• The minute, denoted as \(MM\), must be between 00 and 59 inclusive.

For example, given the digits 1 2 3 4, one possible arrangement is 23:41, which is the largest valid time that can be obtained from these digits.

If there is no valid time, output an empty string.

inputFormat

The input consists of a single line containing four space-separated digits.

Example: 1 2 3 4

outputFormat

Output a single line containing the largest valid time in 24-hour format (HH:MM). If no valid time can be formed, output an empty string.

1 2 3 4

23:41