Looking for help with ARM cortex commands

1. An array of ten (10) 32-bit signed integers is stored in memory starting from address 0x20004000. Write an assembly program to add the even numbered elements of the array (i.e. a[0]+a[2]=) and store the result in R0. Use post-index addressing to access the array elements in memory, i.e., the array elements should be retrieved from memory using post-index addressing. Odd numbered elements of the array should not be accessed. You must make use of a loop.