Nested lists

Read a string with digits from the input and convert each number of the string to an integer. For your newly created list, calculate the running average according to the following formula:

$$A_i = \frac{x_i + x_{i+1}}{2},$$ where $x_i$ and $x_{i+1}$ are elements of the original list, $A_i$ is the element of the moving average. For instance, if your string is 123, an average of 1 and 2 will be 1.5, and an average of 2 and 3 will be 2.5.

Print the result. Notice that this list will have one less item.