"""

想定解 v1.0

"""

import sys
from sys import stdin

N = int(input())

assert 1 <= N <= 10**18

for k in range(2,65):

    A = [0] * (k-1) + [1]
    nsum = 1

    while A[-1] <= N:

        A.append(nsum)
        nsum += A[-1]
        nsum -= A[-k-1]

    if N in A:
        print (k)
        sys.exit()

print (-1)