166. Editor

1. english lowercase letters or spaces: insert this letter in the current position of the cursor.
   
2. L: move cursor one position left. If current position in the beginning of the line, cursor mustn't move.
   
3. R: move cursor one position right. If the current position if after the end of the line, cursor must go beyond this end. If an english lowercase letter or space follows in command line, additional spaces must be added to the text.
   
4. U: move cursor a line up. If the current line is the first, cursor mustn't move.
   
5. D: move cursor a line down. If the current line is last, cursor mustn't move.
   
6. N: a new line must be added after the current. The part of the current line, which goes after the cursor position, must go on the new line. The cursor must go on the first position of the new line.
   
7. E: a cursor must move to a position after the end of the curent line.
   
8. H: a cursor must move to the first position of the current line.
   
9. X: current symbol must be deleted. The remaining part of the line must shift left. If the current position is after the end of the current line, additional spaces must be added to the current line and the next line must be attached to the current line; if the current position is after the end of the last line, nothing must happen.
   
10. B: the symbol before the the cursor must be deleted and the remaining part of the line must shift left. If the current position if after the end of the line, cursor must shift left one position. If the current symbol is the first of the line, then current line must be attached to the previous and remaining part must shift up; if the current symbol is the first symbol of the first line, nothing must happen.
    
11. Q: the editor must finish the work.