## Problem B: Factstone Benchmark

Amtel has announced that it will release a 128-bit computer chip by 2010,
a 256-bit computer by 2020, and so on, continuing its strategy of
doubling the word-size every ten years. (Amtel released a 64-bit
computer in 2000, a 32-bit computer in 1990, a 16-bit computer in 1980,
an 8-bit computer in 1970, and a 4-bit computer, its first, in 1960.)
Amtel will use a new benchmark - the *Factstone* - to advertise
the vastly improved capacity of its new chips. The *Factstone* rating is
defined to be the largest integer *n* such that *n!* can
be represented as an unsigned integer in a computer word.

Given a year *1960 ≤ y ≤ 2160*, what will be the
*Factstone* rating of Amtel's most recently released chip?

There are several test cases. For each test case, there is one
line of input containing *y*. A line containing 0 follows
the last test case. For each test case, output a line giving the
Factstone rating.

### Sample Input

1960
1981
0

### Output for Sample Input

3
8

*Charles L. A. Clarke and Gordon V. Cormack*