-----Description-----  
This task involves updating an array of integers such that the element at a specified index is set to 60 while all other elements remain unchanged.

-----Input-----  
The input consists of:  
• a: An array of integers.  
• j: A natural number representing the index (0-indexed) to update. It is assumed that j is a valid index (j < a.size).

-----Output-----  
The output is an array of integers where:  
• The element at index j is set to 60.  
• All other elements remain the same as in the input array.

-----Note-----  
It is assumed that j is a valid index (0 ≤ j < a.size).