Palindrome Index - iterative solution

PalindromeIndex4.cs

using System;
using System.Collections.Generic;
using System.IO;
class Solution {
    static void Main(String[] args) {
        int numTests = int.Parse(Console.ReadLine());
        
        for(int t = 0; t < numTests; ++t) {
            string s = Console.ReadLine();
            
            int i = 0, j = s.Length - 1;
            int remove_pos = -1;
            while(i < j) {
                if(s[i] != s[j]) {
                    // detect if we need to remove i or j
                    remove_pos = s[i+1] == s[j] && s[i+2] == s[j-1] ? i : j;
                    break;
                }                
                i++;
                j--;
            }
            Console.WriteLine(remove_pos);
        }
    }
}