Fractions whose numerator is 1 are called fractional units, such as (1/1), (1/2), (1/3), (1/4), ..., some unit fractions can be split into two denominators are adjacent natural numbers The difference of the unit fraction, such as (1/6)=(1/2)-(1/3), (1/12)=(1/3)-(1/4), (1/20)=( 1/4)-(1/5), then in the unit fractions (1/2), (1/3), (1/4), ... (1/100), how many cannot be split according to the above requirements indivual.
分子是1的分数叫做分数单位，如(1/1)，(1/2)、(1/3)、(1/4)，…，某些单位分数可以拆成两个分母是相邻自然数的单位分数的差，如(1/6)=(1/2)-(1/3)，(1/12)=(1/3)-(1/4)，(1/20)=(1/4)-(1/5)，则在单位分数(1/2)、(1/3)、(1/4)，…(1/100)中，不能按上述要求拆分的有多少个．
<gadget id="calculator">9 * 10</gadget>
<output>90</output>

<result>90</result>