Step 1 :
Divide $ 8602 $ by $ 4278 $ and get the remainder

$$ 8602 : 4278 = 2 \text{ ( remainder is } \color{blue}{ 46 } \text{ ) } $$

The remainder is positive ($ 46 > 0 $), so we will continue with division.

Step 2 :
Divide $ 4278 $ by $ \color{blue}{ 46 } $ and get the remainder

$$ 4278 : \color{blue}{ \boxed { 46 }} = 93 \text{ ( remainder is } \color{blue}{ 0 } \text{ ) } $$

The remainder is zero => GCD is the last divisor $ \color{blue}{ \boxed { 46 }} $.

This solution can be visualized using a Venn diagram.

The GCD equals the product of the numbers at the intersection.

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