1. A method of inputting letters, the method comprising: pressing one of or sequentially pressing two of basic elements , , , , , , , , , and obtained by separating and symbolizing strokes of letters; determining a letter corresponding to the pressed basic element or the sequentially pressed basic elements; and displaying the determined letter, wherein the basic element is used as a center element, wherein the basic elements , , , and are respectively assigned directly to top, bottom, left and right sides of the center element.