jízuòbiāoxì
ㄐㄧˊ ㄗㄨㄛˋ ㄅㄧㄠ ㄒㄧˋ
Simplified 极坐标系
Taivo → Settings → Partner inbox → Make the link. It stays in this browser.
Keep 極座標系 and it comes back until you know it.