Failed to parse the problem -- EOL while scanning string literal (, line 43)

i am fetting error : /tmp/solver_planning_domains_tmp_2lmCSmQMYFyo5/problem.pddl: syntax error in line 14, '0':
'define' expected

my problem.pddl is

    (define (problem klotski)
  (:domain klotski)

 
  (:objects
    piece2x2 - piece
    piece2x1 - piece
    piece1x2-1 piece1x2-2 piece1x2-3 piece1x2-4 - piece
    piece1x1-1 piece1x1-2 piece1x1-3 piece1x1-4 - piece
    exit - piece
  )

  (:init
    (at piece2x2 0 0)
    (at piece2x1 0 2)
    (at piece1x2-1 0 4)
    (at piece1x2-2 2 0)
    (at piece1x2-3 2 2)
    (at piece1x2-4 2 4)
    (at piece1x1-1 3 0)
    (at piece1x1-2 3 1)
    (at piece1x1-3 3 3)
    (at piece1x1-4 3 4)
    (at exit 1 4)
    (empty 1 0) (empty 1 1) (empty 1 3) (empty 1 4)
    (empty 2 1) (empty 2 3) (empty 3 2)
  )


  (:goal
    (and
      (at piece2x2 1 3)
      (empty 0 0) (empty 0 1) (empty 0 3) (empty 0 4)
      (empty 2 0) (empty 2 1) (empty 2 3) (empty 2 4)
      (empty 3 0) (empty 3 1) (empty 3 3) (empty 3 4)
      (empty 1 1) (empty 1 3) (empty 2 1) (empty 2 3)
    )
  )
)

where is the problem?
the assignment is - Klotski is a sliding puzzle problem. There is one 2×2 piece, one 2 × 1 piece, four 1 × 2 pieces, and four 1 × 1 pieces. Initially, the pieces are placed on a 4 × 5 board, as shown in the following Figure. The goal of the game is to slide the 2 × 2 piece to the exit. No pieces can be removed from the board and pieces can only be slid to the empty spaces horizontally or vertically.

Don't think you should be using raw numbers in fluents like that. 3 should be num3, etc.