import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String s = scan.next();
		scan.close();
		if(s.length() < 3) {
			System.out.println(0);
			System.exit(0);
		}
		System.out.println(cww(s));
	}
	static int cww(String s) {
		int l = s.length();
		if(l < 3) {
			return 0;
		}

		int max = 0;
		String s1 = "";
		String s2 = "";
		for(int i = 0; i < l - 2; i++) {
			char c1 = s.charAt(i);
			if(c1 == 0) {
				continue;
			}
			for(int j = i + 1; j < l - 1; j++) {
				char c2 = s.charAt(j);
				if(c2 == c1) {
					continue;
				}
				for(int k = j + 1; k < l; k++) {
					char c3 = s.charAt(k);
					int p = 0;
					if(c2 == c3) {
						p += 100 * Character.getNumericValue(c1);
						p += 10 * Character.getNumericValue(c2);
						p += Character.getNumericValue(c3);
						s1 = String.valueOf(c1);
						s2 = String.valueOf(c2);
						StringBuilder sb = new StringBuilder(s);
						sb.deleteCharAt(sb.indexOf(s1));
						sb.deleteCharAt(sb.indexOf(s2));
						sb.deleteCharAt(sb.indexOf(s2));
						max = Math.max(max, p + cww(sb.toString()));
					}
				}
			}
		}
		return max;
	}
}