'''
Reciprocal cycles
Problem 26
A unit fraction contains 1 in the numerator. The decimal representation of the unit fractions with denominators 2 to 10 are given:

1/2	= 	0.5
1/3	= 	0.(3)
1/4	= 	0.25
1/5	= 	0.2
1/6	= 	0.1(6)
1/7	= 	0.(142857)
1/8	= 	0.125
1/9	= 	0.(1)
1/10	= 	0.1
Where 0.1(6) means 0.166666..., and has a 1-digit recurring cycle. It can be seen that 1/7 has a 6-digit recurring cycle.

Find the value of d < 1000 for which 1/d contains the longest recurring cycle in its decimal fraction part.
'''


def cycle_length(num):
    r = 10
    i = 0

    while r != 10 or i < 1:
        r = (r % num) * 10
        i += 1
    return i
longest = 0
for i in range(2, 1000):
    if i % 2 != 0 and i % 5 != 0:
        length = cycle_length(i)
        if length > longest:
            longest = length
            result = i
print(result)