shopping_list = ["banana", "orange", "apple"]

stock = {
    "banana": 6,
    "apple": 0,
    "orange": 32,
    "pear": 15
}

prices = {
    "banana": 4,
    "apple": 2,
    "orange": 1.5,
    "pear": 3
}

# Write your code below!
def compute_bill(food):
        total = 0
        for i in food:
            if stock[i] > 0:
                total += prices[i]
                stock[i] = stock[i] - 1
        return total