from decimal import Decimal
import math
import numpy as np
def fibgen(n):
   a,b = 0,1
   while True:
        yield a
        a, b = b, a + b

def F():
    a,b = 0,1
    while True:
        yield a
        a, b = b, a + b

def SubFib(startNumber, endNumber):
    for cur in F():
        print(cur)
        if cur > endNumber: return
        if cur >= startNumber:
            yield cur

for i in SubFib(5, 57000):
    if(int(math.log10(i)+1) == 1000):
        #print(i)
        break

# n=5000
# while True:
   #  if(int(math.log10(fibgen(n))+1) == 1000):
#         print(n)
#         break
#     n += 1