You want to plan a big birthday party with your friends. On planning you notice that you have to do a lot of operations with sets of friends. There is one group which consist of Arthur, Biene and Clemens. Then there is a group of friends you know from snowboarding which consists of Daniel, Ernst, Frida and Gustav. If you want to invite them both, the resulting party group consists of g1 + g2 (the result is the union of both groups). Then you can compute the intersection of the two groups g1 * g2, which consists of the empty set. Maybe you want to invite a group g1, but excluding all members of an other group g2, which is written as g1 - g2.

Intersection (*) has precedence over union (+) and set difference (-). All operations are left associative, which means that in A op_{1} B op_{2} C you first have to evaluate A op_{1} B (provided op_{1} and op_{2} have equal precedence).

Intersection (*) has precedence over union (+) and set difference (-). All operations are left associative, which means that in A op

The input consists of one or more lines. Each line contains one expression that you have to evaluate. Expressions are syntactically correct and only consist of the characters:
'{' and '}'
the elements 'A' to 'Z' meaning friend Arthur to Zora.
the operations '+', '-' and '*'
'(' and ')' for grouping operations
the newline character '\n' marking the end of an expression.
A line is never longer than 255 characters.

Output the resulting set in curly braces '{' and '}', each on a line of its own. Print elements of sets sorted alphabetically.

提交代码