# Odd or even

Number Theory Level 3

Let $$a_1, a_2, \ldots , a_{169}$$ represent any arbitrary permutation of the numbers 1 to 169 inclusive.

Then the product of $${ (a }_{ 1 }-1)({ a }_{ 2 }-2) \ldots ({ a }_{ 169 }-169)$$ is?

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