Question 5
Given four distinct non-zero digits a, b, c and d, if $\overline{ab}+\overline{cd}=\overline{dc}+\overline{ba}$ , then this expression is called a palindrome expression and the sum of the two numbers $\overline{ab}+\overline{cd}$ is called a palindrome sum. For example, $53+46=64+35=99$ . What is the minimum possible value of a palindrome sum?