def isSorted(arr):
    if len(arr)==0 or len(arr)==1:
        return True # because list of length 0 or 1 are already sorted
    
    if arr[0] > arr[1]: # checking if the first element is greater than the second element because then the list won't be 
        return False    # a sorted list
    
    #now we are going to send the smaller list which is the entire list except the first element again for checking the sorted order
    
    if isSorted(arr[1:] # this is the "most hearbreaking step" because we are sending a copy of the list again to our function which will be consuming a lot of space.
               ): 
        return True
    else:
        return False

arr=[1,3,4,7,3,6,9,0]
print(isSorted(arr))

arr = [1,2,5,9,15]
print(isSorted(arr))