69. Fill the 12 natural numbers from 11∼22 into the small circles in the figure, each number must be used, and the sum of the four numbers on each side must be equal. The difference between the minimum and maximum value of this sum is .
A number or a short expression. Fractions can be typed as 3/2, and spacing doesn't matter.
Official solution
Answer: 8
Source: NuminaMath-1.5,
licensed Apache-2.0.
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