SimmetriyaDerecesi

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {

        Scanner scan = new Scanner(System.in);

        int n = scan.nextInt();
        int cN = n;
        int count = 0;

        for (int i = 0; i < cN; cN/=10, count++);

        int arr[] = new int[count];

        for (int i = 0; i < arr.length; i++, n/=10) arr[i] = n%10;

        int simmetriyaDerecesi = 0;

        for (int i = 0; i < (arr.length+1)/2; i++){
             if (arr[i] == arr[arr.length - (i+1)]){
                simmetriyaDerecesi++;
            }
        }

        System.out.println(simmetriyaDerecesi);

    }

}