You generate real numbers s1, s2, ..., sn as follows:

• s0 = 0;
• si = si - 1 + ti, where ti is a real number chosen independently uniformly at random between 0 and 1, inclusive.

You are given real numbers x1, x2, ..., xn. You are interested in the probability that si ≤ xi is true for all i simultaneously.

It can be shown that this can be represented as $$\frac{p}{q}$$, where P and Q are coprime integers, and $$Q \not\equiv 0 \pmod{998244353}$$. Print the value of P·Q - 1 modulo 998244353.

Input

The first line contains integer n (1 ≤ n ≤ 30).

The next n lines contain real numbers x1, x2, ..., xn, given with at most six digits after the decimal point (0 < xi ≤ n).

Output

Print a single integer, the answer to the problem.

见题面 Input 部分

见题面 Output 部分

In the first example, the sought probability is 1 since the sum of i real numbers which don't exceed 1 doesn't exceed i.

In the second example, the probability is x1 itself.

In the third example, the sought probability is 3 / 8.