# 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 index of the first term in the Fibonacci sequence to contain 1000 digits?

from time import time
start = time()

a,b = 1,1
somme = 0
resultat = 2

while len(str(b)) < 1000 :
    a, b = b, a+b
    resultat += 1
    
print(resultat)
print("Temps : " + str(time() - start))
