Validate the Reversible Reference

Intermediate

A reference-number scheme is designed to read identically forwards and backwards as a self-check. Verify whether a given reference is valid under that rule.

Implement `solve(String input)` to return true if `input` reads the same forwards and backwards, false otherwise.

Examples

Input"racecar"

Outputtrue

Input"apex"

Outputfalse

Hints

Compare characters from both ends inward; any mismatch means it is not a palindrome.

Anonymous Apex

Boolean solve(String input) {
    // return true if input is a palindrome
    return null;
}

Your code runs in a secure sandbox against multiple hidden test cases. The problem is solved only when every test passes. Each run is isolated and any data changes are rolled back automatically.