The Fibonacci code is a universal code which encodes smaller numbers into shorter code words. All tokens end with "11" and have no "11" before the end. The code begins as follows:

1  11
2  011
3  0011
4  1011
5  00011
6  10011
7  01011
8  000011
9  100011
10 010011
11 001011
12 101011
To decode a token in the code, remove the last "1", assign the remaining bits the values 1,2,3,5,8,13... (the Fibonacci numbers), and add the "1" bits.