Given a string expression representing a nested ternary expression, evaluate the expression and return its result as a string.

You can assume that the ternary expression evaluates from right to left.

Constraints:

• $5 \leq$ expression.length $\leq 10^4$

• expression consists of digits, 'T', 'F', '?', and ':'.

• It is guaranteed that expression is a valid ternary expression and that each number is a single digit number.

Now, let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Implement your solution in the following coding playground.