import java.io.BufferedReader;
import java.io.InputStreamReader;

public class No256 {
    public static void main(String[] args) {
        try {
            BufferedReader br = new BufferedReader(new InputStreamReader(
                    System.in));
            char[] cArray = br.readLine().toCharArray();
            int maxIdx = -1;
            char maxChar = '/';

            for (int i = 0; i < cArray.length; i++) {
                if (maxChar < cArray[i]) {
                    maxChar = cArray[i];
                    maxIdx = i;
                }
            }
            swap(cArray, 0, maxIdx);
            maxIdx = -1;
            maxChar = '/';
            for (int i = 1; i < cArray.length; i++) {
                if (maxChar < cArray[i]) {
                    maxChar = cArray[i];
                    maxIdx = i;
                }
            }
            swap(cArray, 1, maxIdx);
            System.out.println(cArray);
        } catch (Exception e) {
            e.printStackTrace();
            System.err.println("Error:" + e.getMessage());
        }
    }

    static void swap(char[] cArray, int i, int j) {
        char tmp = cArray[i];
        cArray[i] = cArray[j];
        cArray[j] = tmp;
    }

    static int[] strToIntArray(String S) {
        String[] strArray = S.split(" ");
        int[] intArray = new int[strArray.length];
        for (int i = 0; i < strArray.length; i++) {
            intArray[i] = Integer.parseInt(strArray[i]);
        }
        return intArray;
    }
}