An Egyptian fraction is the sum of distinct unit fractions, such as \tfrac{1}{2}+\tfrac{1}{3}+\tfrac{1}{16}. That is, each fraction in the series has a numerator equal to 1 and a denominator that is a positive integer, and all the denominators differ from each other. The sum of an expression of this type is a positive rational number a/b; for instance the Egyptian fraction above sums to 43/48.