URI Online Judge | 1985

MacPRONALTS

By Victor Jatobá, UNIME BR Brazil

Timelimit: 1

The MacPRONALTS is with a super promotion, exclusive to the contestants of the first Selective MaratonaTEC. But they had a problem, all runners were trying to buy at the same time, so this generated a very long queue. The worst is that the cashier girl no have calculator or a program to help her to calculate more quickly. You are the person that will help the girl and the MacPRONALTS increase their sells. Bellow has a menu day, that contains the product number and its value.

1001 | R$ 1.50

1002 | R$ 2.50

1003 | R$ 3.50

1004 | R$ 4.50

1005 | R$ 5.50

Input

The first entry is reported the number of purchased products (1 <= p <= 5). For each product follows the quantity (1 <= q <= 500) that the customer purchased.

Obs .: the product number will not be repeated.

Output

You must print the purchase amount with two decimal places.

Input Sample Output Sample

2

1001 2

1005 3

19.50

1

1003 500

1750.00

5

1001 500

1005 300

1003 23

1002 52

1004 44

2808.50