The primorial of a number is the product of all the primes until that number, itself included.

Take a number from `STDIN` as the input and evaluate its primorial, also known as the prime factorial.

Don't use libraries. Shortest code wins.

**Test cases:**

```
1 1
2 2
3 6
4 6
5 30
6 30
7 210
8 210
9 210
10 210
11 2310
12 2310
13 30030
14 30030
15 30030
16 30030
17 510510
18 510510
19 9699690

```