predefine.S

.data
_prompt: .asciiz "Enter an integer:"
_ret: .asciiz "\n"

.globl main

.text
read:
  li $v0, 4
  la $a0, _prompt
  syscall
  li $v0, 5
  syscall
  jr $ra

write:
  li $v0, 1
  syscall
  li $v0, 4
  la $a0, _ret
  syscall
  move $v0, $0
  jr $ra