new
dequeue!
empty 1
size 0
enqueue 56
enqueue 78
enqueue 90
dequeue 56
enqueue 123
dequeue 78
dequeue 90
head 123
dequeue 123
head! 
enqueue 1
enqueue 5
enqueue 7
enqueue 9
enqueue 12
enqueue 16
enqueue 22
enqueue 27
enqueue 29
enqueue 31
size 10
delete
new: 1
enqueue 1
capacity 1
enqueue 5
capacity 2
delete
summary
exit