# Problem 60: Prime pair sets

The primes 3, 7, 109, and 673, are quite remarkable. By taking any two
primes and concatenating them in any order the result will always be
prime. For example, taking 7 and 109, both 7109 and 1097 are prime. The
sum of these four primes, 792, represents the lowest sum for a set of
four primes with this property. Find the lowest sum for a set of five
primes for which any two primes concatenate to produce another prime.