function main()
  N = parse(Int, readline())
  L = [BigInt(1), 1]
  for i in 3:100000
    push!(L, L[i - 2] + L[i - 1])
  end
  ans = -1
  for i in 1:100000
    if L[i] % N == 0
      ans = i
      break
    end
  end
  println(ans)
end
main()