For instance, to look up the character where the sound is not known, e.g., 松 (pine tree), the user first determines which part of the character is the radical (here 木), then counts the number of strokes in the radical (four), and turns to the radical index (usually located on the inside front or back cover of the dictionary). Under the number "4" for radical stroke count, the user locates 木, then turns to the page number listed, which is the start of the listing of all the characters containing this radical. This page will have a sub-index giving remainder stroke numbers (for the non-radical portions of characters) and page numbers. The right half of the character also contains four strokes, so the user locates the number 4, and turns to the page number given. From there, the user must scan the entries to locate the character he or she is seeking. Some dictionaries have a sub-index which lists every character containing each radical, and if the user knows the number of strokes in the non-radical portion of the character, he or she can locate the correct page directly.

What contains four strokes?