There are two types of potions:

1. Growing potion: "A"
2. Shrinking potion: "B"

• If "A" immediately follows a digit, add 1 to the digit.
• If "B" immediately follows a digit, subtract 1 from the digit.

Create a function that returns a string according to these rules, removing the potions once they've been consumed.

Examples

"3A78B51" ➞ "47751"
# 3 grows to 4, 8 shrinks to 7

"9A999B" ➞ "10998"
# First 9 grows to 10 and second 9 shrinks to 8

"6A123" ➞ "7123"
# 6 grows to 7

"567" ➞ "567"
# No change

Notes

• Digits that do not have a potion on their immediate right should be left alone.
• A digit will always either be followed by zero or exactly 1 potion.
• There won't be any 0 in the given string.