euler025.py

#!/usr/bin/python3
# -*- coding: utf-8 -*-
################################################################################
# Euler 25
# 1000-digit Fibonacci number
# Author: Eugene Kolo - 2014
# Contact: www.eugenekolo.com

# 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?
################################################################################
def solve():
    from eulerlib import fib
    n = 0
    while (len(str(fib(n))) < 1000):
        n +=1
    return n

if __name__ == '__main__':
    print(solve())