You will be given a definition of a task first, then some input of the task.
In this task you are given a list of numbers and you need to find the average of each two consecutive values. The average of two numbers a and b is calculated as: (a + b) /2. The output should be a list of the averages of each two consecutive values. A list is presented with two brackets and comma-separated values, like: [1,2,3].

[-31, -98, -40, -50, -42, -86, 56, 45, -81, 77]
Output:
[-64.5, -69.0, -45.0, -46.0, -64.0, -15.0, 50.5, -18.0, -2.0]