\startuseMPgraphic{squareBox}
draw topboundary OverlayBox leftenlarged 1mm rightenlarged 1mm;
draw bottomboundary OverlayBox leftenlarged 1mm rightenlarged 1mm;
draw rightboundary OverlayBox shifted (1mm,0);
draw leftboundary OverlayBox shifted (-1mm,0);
\stopuseMPgraphic
\defineoverlay
[headerBox]
[\useMPgraphic{squareBox}]
\startuseMPgraphic{verticalrule3}
draw rightboundary OverlayBox shifted (1mm,0); %if CurrentColumn = 1: shifted(-2mm,0) fi ;
draw leftboundary OverlayBox shifted (-1mm,0); %if CurrentColumn = 2: shifted(2mm,0) fi ;
draw bottomboundary OverlayBox leftenlarged 1mm rightenlarged 1mm;
\stopuseMPgraphic
\defineoverlay
[verticalrule]
[\useMPgraphic{verticalrule3}]
\definecolumnset
[exam]
[n=2,
background=verticalrule]
\setuplayout[width=19cm, height=26cm, header=1cm, footer=.5cm,backspace=1cm]
\setupheader[before=\vfil, after=\vfil]
\setupbackgrounds[header][text][frame=off, background=headerBox, align=lohi]%topframe=
\setupbackgrounds[footer][text][frame=off, background=screen]
\define[3]\headTitle{\setupheadertexts[][\bf #1 \hfill #2 \hfill #3 \hfill ID: \hskip 2cm Name: \hskip 2cm]}
\setupmathematics[autopunctuation=no, integral=nolimits]
\setupbodyfont[rm,10pt]
\setuppagenumbering[location=footer]
\setupcolors[state=start]
%\setupexternalfigure[directory={/Users/graph/Documents/figures,}]
\headTitle{2021. 12. 12.}{Set Theory}{Final Exam}
\starttext
\startcolumnset[exam]
\startitemize[n]
\item The first problem.
\column
\item The second problem.
\column
\item The third problem.
\column
\item The third problem.
\stopitemize
\stopcolumnset
\stoptext