A Splendid Catch
If you have a fret-saw, cut out the letters forming the word last, adhering as much as possible to the shapes of the letters shown in the diagram. Use thin wood for the purpose. Then, set out the letters as we have given them and ask your friends to change the last into first. They can employ any method they like as long as they do not want use anything beyond the four pieces you have set before them. It is only rarely that anyone spots the solution; it is merely to leave out the letter a . Without this letter you have 1st.