JSFiddle - React, Tailwind, and code Playground
HTML
<canvas id=c>JavaScript
a=40,w=80,x=c.getContext`2d`;c=(X,Y)=>{x.beginPath();x.arc(X*a+20,Y*a+20,15,0,7);x.fill()};[0,1,2,3].map(o=>x.strokeRect((o&1)*a,(o&2)*20,w,w)),c(1,0),c(2,1),c(0,2),c(1,2),c(2,2)