{
  "analysis": "Partial updates are slightly better for this row (73 vs 84 bytes). But I need to consider cursor positioning between rows. Let me calculate total cost with a line-based strategy using relative movements.",
  "plan": "Calculate the total cost with an optimized line-based strategy that uses relative cursor movements and chooses between EL+rewrite vs partial updates per line.",
  "commands": [
    {
      "keystrokes": "python3 -c \"\nimport struct\n\ndef cost_move(from_r, from_c, to_r, to_c):\n    if from_r == to_r and from_c == to_c:\n        return 0\n    if from_r == to_r:\n        dc = to_c - from_c\n        if dc > 0:\n            return 4 + len(str(dc))  # ESC[nC\n        else:\n            return 4 + len(str(-dc))  # ESC[nD\n    # Different rows: use CR + CUD/CUU + CUF\n    cost = 1  # CR\n    dr = to_r - from_r\n    if dr > 0:\n        cost += 4 + len(str(dr))  # ESC[nB\n    elif dr < 0:\n        cost += 4 + len(str(-dr))  # ESC[nA\n    if to_c > 1:\n        cost += 4 + len(str(to_c - 1))  # ESC[nC\n    return cost\n\nwith open('/app/frames.tza', 'rb') as f:\n    f.read(4)\n    w, h = struct.unpack('<HH', f.read(4))\n    n_frames, max_bytes = struct.unpack('<II', f.read(8))\n    \n    frames = []\n    for i in range(n_frames):\n        frames.append(f.read(w*h))\n\n# First frame: write non-space chars in row-major order\ntotal_cost = 0\nnon_space_positions = [(j//w, j%w) for j in range(w*h) if frames[0][j] != 32]\nprint(f'Frame 0 non-space: {len(non_space_positions)}')\n\n# Cost to write non-space chars\nif non_space_positions:\n    # Move to first non-space\n    total_cost += 0  # already at (1,1)\n    cursor_r, cursor_c = non_space_positions[0][0] + 1, non_space_positions[0][1] + 1\n    \n    # Write all non-space chars\n    for r, c in non_space_positions:\n        if r == cursor_r - 1 and c == cursor_c:\n            # Already in position (contiguous)\n            cursor_c += 1\n        else:\n            total_cost += cost_move(cursor_r, cursor_c, r + 1, c + 1)\n            cursor_r, cursor_c = r + 1, c + 1\n            cursor_c += 1  # after writing\n    total_cost += len(non_space_positions) + 1  # chars + delimiter\nelse:\n    total_cost += 1  # just delimiter\n\nprint(f'Frame 0 cost: {total_cost}')\n\n# Calculate cost for all frames using line-based strategy\ncursor_r, cursor_c = h, 1  # After writing frame 0, assume cursor at end\n\nfor i in range(1, n_frames):\n    changed_rows = []\n    for r in range(h):\n        if frames[i-1][r*w:(r+1)*w] != frames[i][r*w:(r+1)*w]:\n            changed_rows.append(r)\n    \n    if not changed_rows:\n        total_cost += 1  # just delimiter\n        continue\n    \n    frame_cost = 0\n    \n    for r in changed_rows:\n        # Analyze this row\n        prev_row = frames[i-1][r*w:(r+1)*w]\n        curr_row = frames[i][r*w:(r+1)*w]\n        changes = [(c, prev_row[c], curr_row[c]) for c in range(w) if prev_row[c] != curr_row[c]]\n        \n        # Find runs\n        runs = []\n        if changes:\n            run_start = changes[0][0]\n            run_end = changes[0][0]\n            for c, _, _ in changes[1:]:\n                if c == run_end + 1:\n                    run_end = c\n                else:\n                    runs.append((run_start, run_end))\n                    run_start = run_end = c\n            runs.append((run_start, run_end))\n        \n        # Cost of EL + rewrite\n        cost_erase = 4 + w  # ESC[2K + rewrite\n        \n        # Cost of partial updates (from current cursor)\n        cost_partial = 0\n        for start, end in runs:\n            cost_partial += cost_move(cursor_r, cursor_c, r + 1, start + 1)\n            cursor_r, cursor_c = r + 1, end + 2  # after writing run\n        cost_partial += len(changes)\n        \n        # Choose cheaper option\n        if cost_erase <= cost_partial:\n            frame_cost += cost_move(cursor_r, cursor_c, r + 1, 1)  # move to start of row\n            frame_cost += 4 + w  # ESC[2K + rewrite\n            cursor_r, cursor_c = r + 1, w + 1\n        else:\n            frame_cost += cost_partial\n    \n    total_cost += frame_cost + 1  # + delimiter\n\nprint(f'Total cost: {total_cost}')\nprint(f'Budget: {max_bytes}')\nprint(f'Over/under: {total_cost - max_bytes}')\n\"\n",
      "duration": 3.0
    }
  ]
}