A word-and-number arrangement machine works on an input line of words and two-digit numbers in steps, and in this machine nothing ever changes place. In each step the leftmost number it has not already dealt with is rubbed out and the difference of its two digits — the larger digit minus the smaller — is written in that same position. Words are never touched, and the machine stops once every number of the line has been dealt with. Input: 52 rice 86 pancake 41 noodles 93. In the last step of the above arrangement, which element is second from the right end?

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noodles. Step 1: 3 rice 86 pancake 41 noodles 93. Step 2: 3 rice 2 pancake 41 noodles 93. Step 3: 3 rice 2 pancake 3 noodles 93. Step 4, the last: 3 rice 2 pancake 3 noodles 6. Counting from the right end — 6, then noodles — the second element is noodles. "6" is first from the right, an off-by-one count. "3" is third from the right. "93" is the number as it stood in the input, forgetting that the last step replaces it by 9 minus 3.

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