This is the ratio of dividing a line segment A into two parts B and C such that A is to B as B is to C.
A
------------+-------
B C
This deceptively simple ratio has fascinated mathematicians for centuries.
It can be written as A/B = B/C.
The ratio A/B is usually designated by the Greek letter phi, and it is approximately equal to 1.618.
Now if your task were to simply output "1.618", it wouldn't be much of a challenge. Printing a text string would do. The challenge is that your entry must print the value of phi for 2400 places after the decimal point, rounded to the nearest value. You may use a text string if you want, but it's very unlikely to be a winning strategy.