Suppose Haruka has a special key $\triangle$ in her caculator called delta key:

Rule 1: If the display shows a one-digit number, pressing delta key $\triangle$ replace the displayed number with twice its value.
Rule 2: If the display shows a two-digits number, pressing delta key $\triangle$ replace the displayed number with the number sum of two digits.
Suppose Haruka enters the value 1 and then presses delta key $\triangle$ repeated.
After pressing the key for 68 times, what will be the displayed number?

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