Outage Probability Calculation

In this problem, you are given an integer n representing the number of minutes in the outage history, and a sequence h of n integers where each integer is either 0 (no outage) or 1 (an outage). Your task is to calculate the probability that the next minute will experience an outage.

The probability is computed using the formula:

$$P = \frac{\text{number of outages}}{n}$$

If n = 0, the probability is defined to be 0.0. The output should be a floating-point number with six decimal places.

inputFormat

The input is given from standard input (stdin) and has the following format:

• The first line contains an integer n, the number of minutes in the history.
• The second line contains n space-separated integers (each either 0 or 1) representing the outage history.

outputFormat

Output a single floating-point number to standard output (stdout) with exactly six decimal places which represents the probability that the next minute will be an outage.

## sample

5
1 1 1 1 1

1.000000

</p>