input: 
  def linearSearch(arr, value):
      """ Create an algorithm for a linear search. The algorithm takes in an array and a 
      value to search for, and returns the index of the value if it is found, or -1 if 
      it is not.
      
      >>> linearSearch([5, 3, 7, 2], 7)
      2
      >>> linearSearch([5, 3, 7, 2], 10)
      -1
      """
  
output:     for i in range(len(arr)):
          if arr[i] == value:
              return i
      return -1