2000/2001 ACM International Collegiate Programming Contest
University of Ulm Local Contest

# Problem F: How many Fibs?

Source file: fibs.(c|C|java|pas)
Input file: fibs.in

Recall the definition of the Fibonacci numbers:

> f1 := 1
> f2 := 2
> fn := fn-1 + fn-2 (n>=3)

Given two numbers a and b, calculate how many Fibonacci numbers are in the range [a,b].

Input Specification

The input contains several test cases. Each test case consists of two non-negative integer numbers a and b. Input is terminated by a=b=0. Otherwise, a<=b<=10100. The numbers a and b are given with no superfluous leading zeros.

Output Specification

For each test case output on a single line the number of Fibonacci numbers fi with a<=fi<=b.

Sample Input

    10 100
    1234567890 9876543210
    0 0

Sample Output

    5
    4