Probability of a Shorter-Than Height

You're sizing sleeping berths for Ridgeline Coach Works, which builds overnight buses. A berth on the drawing has a fixed clear length, and the sales team needs a line in the brochure saying what share of passengers it fits without them having to curl up.

The engineers' population reference treats the measurement in question as normally distributed with a stated mean and standard deviation. Ridgeline builds for several markets and quotes several fittings, so the reference figures and the cutoff both change from one brochure line to the next. The berth is a single fixed length, so the only question is how much of that population falls underneath it.

Task: Print the probability that a randomly chosen person from this population measures less than the cutoff - the left-hand tail of the normal model described above - rounded to 4 decimals.

Input

Three lines: the population mean, the population standard deviation, and the cutoff being asked about. All three are decimals, and the standard deviation is positive.

Output

One line holding the probability, rounded to 4 decimals and printed the way Python prints a float - 0.8413.

Example:

Input:
70
3
73

Output:
0.8413