Print A
Length A
Load A file1
Print A
Length A
Load B file2
Print B
LOAD C file3
Common A B C
Print C
Length C
Merge A B D
Print D
Length D
Diff A B C
Print C
Length C
Diff B A C
Print C
Length C
Copy A E
Print E
Length E
Erase E
Print E
Length E
IsIn A Dan
IsIn B Dan
Add A Bob the Builder
Print A
Add A Natalie Portman
Print A
Delete A Natalie Portman
Print A
Delete A Natalie Portman
Merge
Merge A
Merge A B
Quit