import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String a = scanner.next();
        StringBuilder flag = new StringBuilder();
        if(a.startsWith("-")){
            a = a.substring(1);
            char[] arr = a.toCharArray();
            int count = reserve(arr);
            if (count != arr.length) {
                flag.append("-");
                for (int i = count; i < arr.length; i++) {
                    flag.append(arr[i]);
                }
            }else{
                flag.append("0");
            }
        }else{
            char[] arr = a.toCharArray();
            int count = reserve(arr);
            if (count != arr.length) {
                for (int i = count; i < arr.length; i++) {
                    flag.append(arr[i]);
                }
            }else{
                flag.append("0");
            }
        }
        System.out.println(flag);
    }

    public static int reserve(char[] arr){
        int count = 0;
        for (int i = 0; i < arr.length / 2; i++) {
            char temp = arr[i];
            arr[i] = arr[arr.length - i - 1];
            arr[arr.length - i - 1] = temp;
        }

            if(arr[0] == '0'){
                if(arr[0] != arr[1]){
                    count = 1;
                }else{
                    for (int i = 0; i < arr.length - 1; i++) {
                        if(arr[i] != arr[i + 1]){
                            count++;
                            break;
                        }
                        count++;
                    }
                }
            }

        return count;
    }
}