-----Description-----  
This problem involves updating an array of integers by modifying two specific positions. Specifically, the element at index 4 should be increased by 3, and the element at index 7 should be changed to 516. The goal is to correctly update these positions while leaving the rest of the array unchanged. The description assumes that the array contains at least 8 elements.

-----Input-----  
The input consists of:  
• a: An array of integers. The array must contain at least 8 elements.

-----Output-----  
The output is an array of integers that meets the following criteria:  
• The element at index 4 is updated to its original value plus 3.  
• The element at index 7 is set to 516.  
• All other elements in the array remain the same as in the input array.

-----Note-----  
It is assumed that the input array has a size of at least 8 elements. Indices are 0-indexed.