Step 1 :
Divide $ 3962 $ by $ 1859 $ and get the remainder

$$ 3962 : 1859 = 2 \text{ ( remainder is } \color{blue}{ 244 } \text{ ) } $$

The remainder is positive ($ 244 > 0 $), so we will continue with division.

Step 2 :
Divide $ 1859 $ by $ \color{blue}{ 244 } $ and get the remainder

$$ 1859 : 244 = 7 \text{ ( remainder is } \color{blue}{ 151 } \text{ ) } $$

The remainder is still positive ($ 151 > 0 $), so we will continue with division.

Step 3 :
Divide $ 244 $ by $ \color{blue}{ 151 } $ and get the remainder

$$ 244 : 151 = 1 \text{ ( remainder is } \color{blue}{ 93 } \text{ ) } $$

The remainder is still positive ($ 93 > 0 $), so we will continue with division.

Step 4 :
Divide $ 151 $ by $ \color{blue}{ 93 } $ and get the remainder

$$ 151 : 93 = 1 \text{ ( remainder is } \color{blue}{ 58 } \text{ ) } $$

The remainder is still positive ($ 58 > 0 $), so we will continue with division.

Step 5 :
Divide $ 93 $ by $ \color{blue}{ 58 } $ and get the remainder

$$ 93 : 58 = 1 \text{ ( remainder is } \color{blue}{ 35 } \text{ ) } $$

The remainder is still positive ($ 35 > 0 $), so we will continue with division.

Step 6 :
Divide $ 58 $ by $ \color{blue}{ 35 } $ and get the remainder

$$ 58 : 35 = 1 \text{ ( remainder is } \color{blue}{ 23 } \text{ ) } $$

The remainder is still positive ($ 23 > 0 $), so we will continue with division.

Step 7 :
Divide $ 35 $ by $ \color{blue}{ 23 } $ and get the remainder

$$ 35 : 23 = 1 \text{ ( remainder is } \color{blue}{ 12 } \text{ ) } $$

The remainder is still positive ($ 12 > 0 $), so we will continue with division.

Step 8 :
Divide $ 23 $ by $ \color{blue}{ 12 } $ and get the remainder

$$ 23 : 12 = 1 \text{ ( remainder is } \color{blue}{ 11 } \text{ ) } $$

The remainder is still positive ($ 11 > 0 $), so we will continue with division.

Step 9 :
Divide $ 12 $ by $ \color{blue}{ 11 } $ and get the remainder

$$ 12 : 11 = 1 \text{ ( remainder is } \color{blue}{ 1 } \text{ ) } $$

The remainder is still positive ($ 1 > 0 $), so we will continue with division.

Step 10 :
Divide $ 11 $ by $ \color{blue}{ 1 } $ and get the remainder

$$ 11 : \color{blue}{ \boxed { 1 }} = 11 \text{ ( remainder is } \color{blue}{ 0 } \text{ ) } $$

The remainder is zero => GCD is the last divisor $ \color{blue}{ \boxed { 1 }} $.

This solution can be visualized using a Venn diagram.

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

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