Lemonade Stand

At a lemonade stand, each lemonade costs $5. Customers are standing in a queue to buy from you, and order one at a time (in the order specified by bills).

Each customer will only buy one lemonade and pay with either a $5, $10, or $20 bill. You must provide the correct change to each customer so that the net transaction is that the customer pays $5.

Return True if and only if you can provide every customer with correct change.

Examples

lemonade([5, 5, 5, 10, 20]) ➞ True

lemonade([5, 5, 10, 10, 20]) ➞ False

lemonade([10, 10]) ➞ False

lemonade([5, 5, 10]) ➞ True

Notes

• You don't have any change in hand at first.
• bills is an integer list.
• bills[i] will be either 5, 10, or 20.