Euler_25

#-------------------------------------------------------------------------------
# Name:        Euler_25
# Purpose:
#
# Author:      Stewart
#
# Created:     25/07/2012
# Copyright:   (c) Stewart 2012
# Licence:     <your licence>
#-------------------------------------------------------------------------------
#!/usr/bin/env python
""""
The Fibonacci sequence is defined by the recurrence relation:

    Fn = Fn?1 + Fn?2, where F1 = 1 and F2 = 1.

Hence the first 12 terms will be:

    F1 = 1
    F2 = 1
    F3 = 2
    F4 = 3
    F5 = 5
    F6 = 8
    F7 = 13
    F8 = 21
    F9 = 34
    F10 = 55
    F11 = 89
    F12 = 144

The 12th term, F12, is the first term to contain three digits.

What is the first term in the Fibonacci sequence to contain 1000 digits?
"""
import math

answer = 0
a, b, c = 1, 1, 0

while answer < 1000:
    a = a + b
    b = b + a
    c+=2
    answer = len(str(a))
print c