Revenue per User

Lantern's finance analyst has the month's revenue arriving in a handful of separate billing lines — annual plans, monthly plans, add-ons — and, separately, the number of people on the platform. The board reads this figure directly against what it costs to win a customer, so it has to come out per user, not per billing line.

Task: Print the month's revenue per user.

Input

The first line holds an integer: the number of users, never zero. The second line holds an integer n, how many revenue amounts follow. Then come n lines, one amount each. There is no relationship between n and the number of users.

Output

One line: the revenue per user with exactly two digits after the decimal point.

Example:

Input:
50
3
500
250
750

Output:
30.00