>(<span class='kw'>grp1</span> <span class='kw'>=</span> <span class='fu'><a href='https://www.rdocumentation.org/packages/base/topics/rep'>rep</a></span>(<span class='no'>LETTERS</span>[<span class='fl'>1</span>:<span class='fl'>3</span>], <span class='kw'>each</span> <span class='kw'>=</span><span class='fl'>4</span>),
                       <span class='kw'>grp2</span> <span class='kw'>=</span> <span class='no'>letters</span>[<span class='fl'>1</span>:<span class='fl'>2</span>],
                       <s