[0], coprime to 1. Therefore, is the trivial group with 1=?(1) = 1 element. Because of its trivial nature, the case of congruences modulo 1 is generally ignored and some authors choose not to include the case of n = 1 in theorem statements.

Modulo 2 there is only one coprime congruence class, [1], so is the trivial group.

Modulo 4 there are two coprime congruence classes, [1] and [3], so the cyclic group with two elements.

Modulo 8 there are four coprime congruence classes, [1],

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