input:     from typing import List
  
      def merge_sort(list1: List[int], list2: List[int]) -> List[int]:
          """ Merge two lists of integers into one sorted list without using the in-built sort function.
          >>> merge_sort([3, 5, 9, 1, 8], [4, 11, 7, 2])
          [1, 2, 3, 4, 5, 7, 8, 9, 11]
          """
          merged_list = list1 + list2
          for i in range(len(merged_list)):
              min_idx = i
              for j in range(i+1, len(merged_list)):
                  if merged_list[min_idx] > merged_list[j]:
                      min_idx = j
              merged_list[i], merged_list[min_idx] = merged_list[min_idx], merged_list[i]
          return merged_list
      
      list1 = [3, 5, 9, 1, 8]
      list2 = [4, 11, 7, 2]
      
      print(merge_sort(list1, list2))
output:     merged_list = list1 + list2
      for i in range(len(merged_list)):
          min_idx = i
          for j in range(i+1, len(merged_list)):
              if merged_list[min_idx] > merged_list[j]:
                  min_idx = j
          merged_list[i], merged_list[min_idx] = merged_list[min_idx], merged_list[i]
      return merged_list