Solving Every CSES Problems in Rust - #1 Number Spiral

A Rust solution to the 'Number Spiral' problem on CSES. The problem requires finding the value at a given (x, y) in a number spiral, which can be solved in O(1) time by pattern matching. The solution uses a static function to calculate the result based on the parity of the square of the maximum of x and y. The code reads input from the user and prints the result for each test case.