Author: 悅璃乃 (えりの)(jpdong@hpu.edu.kg)

The Number Guessing Game

When three walk together, seventy is rare; Twenty-one branches of plum blossoms on five trees; Seven sons reunite at half-moon; Subtract one hundred and five, the answer appears.

——— (Ming Dynasty) Cheng Dawei, Suanfa Tongzong (General Collection of Arithmetic Methods)

The first time I became interested in the “Chinese Remainder Theorem” was simply because its name stood out so uniquely among all theorems. Its solution method, “Qin Jiushao’s Dayan Qiuyi Shu (The Art of Seeking One)”, is also an exceptionally elegant and sacred name that can spark boundless imagination in a high school student. This sacred piece of mathematics comes from the Sunzi Suanjing (The Mathematical Classic of Master Sun) from the Northern and Southern Dynasties—not the military strategist Sunzi who led troops during the Spring and Autumn period, but a mathematician surnamed Sun from that later era. The famous “chickens and rabbits in the same cage” problem also originates from this book.

Published on 2026-07-25 at 閑時茶話, last modified on 2026-07-25

Author: 悅璃乃 (えりの)(jpdong@hpu.edu.kg)

I must confess: whenever I face a major event—especially a critical turning point in life—I can’t help but feel an itch to “fool around.”

Right now, amid the stifling atmosphere of preparing for the postgraduate entrance exam, I find myself eagerly typing out the first post of this new site in front of my computer screen. This scene feels oddly familiar. It takes me back to the spring and summer of 2022, when I was on a leave of absence from high school and staying at home. Back then, I had just shed my old ways of thinking and absorbed some new perspectives, which gave me a clearer sense of my future and life goals. In that era before AI was everywhere and you had to bang your head against every wall alone, I followed online tutorials with sheer grit and built the first website in my life.

Published on 2026-07-22 at 閑時茶話, last modified on 2026-07-22

Author: 悅璃乃 (えりの)(jpdong@hpu.edu.kg)

Many beginners encounter this issue when using a VPS: the provider’s control panel assigns an IPv4 address and a full /64 IPv6 range, but the system only has IPv4 or IPv6, or the panel shows “No IP”. Below, I’ll share step by step the process of getting a Debian 12 VPS from “no network info” to successfully enabling IPv4 + IPv6, hoping to provide some reference for newcomers.

Prerequisites: Obtain the Information from Your Provider

Before starting, you need to check the network information assigned to you from the provider’s control panel:

Published on 2026-07-23 at 閑時茶話, last modified on 2026-05-07