#816. Warehouse
You get commands: `add item k` (add k pieces) and `remove item k` (take away k pieces, but never below 0). At the end, print the items that have more than 0 left as `item count`, in alphabetical order. If nothing is left, print `Empty`.
### Input
n, then n lines with commands.
### Output
Lines.
Examples
Input
4 remove book 6 add ball 2 add pen 6 remove pen 6
Output
ball 2
Input
8 add pen 9 remove pen 5 add book 2 remove book 1 add book 9 add ball 8 add book 3 add pen 7
Output
ball 8 book 13 pen 11
💡 You can solve it with Python, JavaScript or blocks. Read the input line by line with input(). Don't print a question (like input("Number: ")). Print exactly what the output asks for, nothing more.