I will show you the most popular board game in the Shanghai Ingress Resistance Team.
It all started several months ago.
We found out the home address of the enlightened agent Icount2three and decided to draw him out.
Millions of missiles were detonated, but some of them failed.
After the event, we analysed the laws of failed attacks.
It's interesting that the $i$-th attacks failed if and only if $i$ can be rewritten as the form of $2^a3^b5^c7^d$ which $a,b,c,d$ are non-negative integers.
At recent dinner parties, we call the integers with the form $2^a3^b5^c7^d$ "I Count Two Three Numbers".
A related board game with a given positive integer $n$ from one agent, asks all participants the smallest "I Count Two Three Number" no smaller than $n$.