一个两位素数，将它的十位数字与个位数字对调后仍是一个两位素数，我们称它为＂美好素数＂，求所有＂美好素数＂之和。

A two-digit prime number is called a ‘beautiful prime’ if, when its tens digit and units digit are swapped, it remains a two-digit prime number. Find the sum of all ‘beautiful primes’.