## Story
John runs a shop, bought some goods, and then sells them. He used a special accounting method, like this:
```
[[60,20],[60,-20]]
```
Each sub array records the commodity price and profit/loss to sell (percentage). Positive mean profit and negative means loss.
In the example above, John's first commodity sold at a price of $60, he made a profit of 20%; Second commodities are sold at a price of $60 too, but he lost 20%.
Please calculate, whether his account is profit or loss in the end?
## Rules
Write a function ```profitLoss```, argument ```records``` is the list of sales.
return a number(positive or negative), round to two decimal places.
## Examples
def profitLoss(records):
    return round(sum(pr * pe / (100+pe) for pr, pe in records), 2)
def profitLoss(records):
    return round(sum(pr * pe / (100+pe) for pr, pe in records), 2)