1 import java.lang.*;
2 import java.math.*;
3 import java.util.*;
4 import java.io.*;
5 import java.lang.*;
6 class Main
7 {
8 public static void main(String[] args)
9 {
10 String a,b,c;
11 int i,len1,len2,len3;
12 BigInteger d[]=new BigInteger[201];
13 BigInteger s1,s2,s3;
14 BigInteger ox1=new BigInteger("0");
15 BigInteger ox2=new BigInteger("26");
16 Scanner cin=new Scanner(System.in);
17 d[0]=BigInteger.valueOf(1);
18 for(i=1;i<200;i++)
19 {
20 d[i]=d[i-1].multiply(BigInteger.valueOf(26));
21 }
22 while(cin.hasNext())
23 {
24 a=cin.next();
25 b=cin.next();
26 len1=a.length();
27 len2=b.length();
28 s1=BigInteger.valueOf(0);
29 s2=BigInteger.valueOf(0);
30 for(i=len1-1;i>=0;i--)
31 {
32 s1=s1.add(BigInteger.valueOf(a.charAt(i)-'A').multiply(d[len1-i-1]));
33 }
34 for(i=len2-1;i>=0;i--)
35 {
36 s2=s2.add(BigInteger.valueOf(b.charAt(i)-'A').multiply(d[len2-i-1]));
37 }
38 s3=s1.add(s2);
39 c="";
40 while(s3.compareTo(ox1)>0)
41 {
42 c=c.concat(String.valueOf((char)(s3.mod(ox2).intValue()+'A')));
43 s3=s3.divide(ox2);
44 }
45 len3=c.length();
46 for(i=len3-1;i>=0;i--)
47 {
48 System.out.print(c.charAt(i));
49 }
50 System.out.println();
51 }
52 }
53 }
