import java.util.*;

public class Antti {
    static String calc(int[] c1, int[] c2) {
        int n = c1.length;
        int[] r = new int[n];
        int k = n;
        for (int i = n-1; i >= 0; i--) {
            if (c1[i]+c2[i] > 9) k = i;
        }
        if (k != n) {
            boolean f = true;
            for (int i = n-1; i >= k; i--) {
                if (c1[i] == 0 && f) continue;
                if (f) r[i] = 10-c1[i];
                else r[i] = 9-c1[i];
                f = false;
            }
            for (int i = k-1; i >= 0; i--) {
                c1[i]++;
                if (c1[i]+c2[i] <= 9) break;
                r[i] = 10-c1[i];
            }
        }
        char[] c = new char[n];
        for (int i = 0; i < n; i++) c[i] = (char)(r[i]+'0');
        return new String(c);
    }

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        String s1 = input.nextLine();
        String s2 = input.nextLine();
        int n1 = s1.length();
        int n2 = s2.length();
        int n = Math.max(n1,n2)+1;
        int[] c1 = new int[n];
        int[] c2 = new int[n];
        for (int i = 0; i < n1; i++) {
            c1[i+n-n1] = s1.charAt(i)-'0';
        }
        for (int i = 0; i < n2; i++) {
            c2[i+n-n2] = s2.charAt(i)-'0';
        }
        String r1 = calc(c1.clone(),c2.clone());
        String r2 = calc(c2.clone(),c1.clone());
        if (r1.compareTo(r2) > 0) r1 = r2;
        boolean f = true;
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < n; i++) {
            if (r1.charAt(i) == '0' && f) continue;
            f = false;
            sb.append(r1.charAt(i));
        }
        System.out.print(sb);
        if (f) System.out.print("0");
        System.out.println();
    }
}