Your professor wants you to find which value A,B,C or D changes in two different indexes. e.g. if he gives 11 and 10,

• for 11: A=1; B=0; C=1; D=1;
• for 10: A=1; B=0: C=1; D=0;

Question:

• You are given 2 numbers. You will give the result only if they are in same row or column, you can't pick 0 and 5 for example.
• Also the numbers must be adjacent or border numbers, for ex. 4 and 6; 0 and 8. You can't have 0 and 12 or 0 and 3.
• The indexes 0-15 are as shown in figure.

Question: Write a program that gets two numbers which are between 0 and 15. Then, your program finds which letter A,B,C or D is different or changes in those indexes.

Input specification
You will be two different numbers between 0 and 15.

Output specification
Show one letter (capital): which value (0 or 1) is different or changes in those indexes. If any of the two restrictions are violated print "ERROR"