{
  "analysis": "I need to try a much more efficient approach. Let me calculate the cost using a smarter strategy: for each changed row, decide between EL+rewrite vs partial updates, and use CR + CUD/CUU to move between rows efficiently.",
  "plan": "Calculate the cost of an optimized strategy that uses CR + vertical moves for row changes and chooses the cheapest update method per row.",
  "commands": [
    {
      "keystrokes": "python3 << 'EOF'\nimport struct\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    frames = [f.read(w*h) for _ in range(n_frames)]\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: CR + vertical move + horizontal\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 from col 1\n    return cost\n\ndef abs_pos_cost(r, c):\n    return 3 + len(str(r)) + 1 + len(str(c))\n\ntotal_cost = 0\n\n# Frame 0: write non-space using runs\nframe0 = frames[0]\ncursor_r, cursor_c = 1, 1\nfor r in range(h):\n    row = frame0[r*w:(r+1)*w]\n    in_run = False\n    run_start = 0\n    for c in range(w):\n        if row[c] != 32:\n            if not in_run:\n                in_run = True\n                run_start = c\n        else:\n            if in_run:\n                in_run = False\n                run_len = c - run_start\n                total_cost += cost_move(cursor_r, cursor_c, r+1, run_start+1) + run_len\n                cursor_r, cursor_c = r+1, run_start+run_len+1\n    if in_run:\n        run_len = w - run_start\n        total_cost += cost_move(cursor_r, cursor_c, r+1, run_start+1) + run_len\n        cursor_r, cursor_c = r+1, run_start+run_len+1\ntotal_cost += 1\nprint(f'Frame 0 cost: {total_cost}')\n\n# Subsequent frames\ncursor_r, cursor_c = 24, 1  # End of frame 0\nfor i in range(1, n_frames):\n    changed_rows = [r for r in range(h) if frames[i-1][r*w:(r+1)*w] != frames[i][r*w:(r+1)*w]]\n    if not changed_rows:\n        total_cost += 1\n        continue\n    \n    for r in changed_rows:\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 = cost_move(cursor_r, cursor_c, r+1, 1) + 4 + w\n        \n        # Cost of partial\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\n        cost_partial += len(changes)\n        \n        if cost_erase <= cost_partial:\n            total_cost += cost_move(cursor_r, cursor_c, r+1, 1) + 4 + w\n            cursor_r, cursor_c = r+1, w+1\n        else:\n            total_cost += cost_partial\n    total_cost += 1\n\nprint(f'Total: {total_cost}, Budget: {max_bytes}, Diff: {total_cost - max_bytes}')\nEOF\n",
      "duration": 5.0
    }
  ]
}