Competitions

# Number of toys

You are given the number of kinds of the toys in the shop, the number of toys of each kind and cost of a toy of each kind. Find the number of toys with cost less than 50 grn.

#### Input

The first line contains the number of kinds of the toys n (0n1000). Each of the next n lines contains 2 numbers: the number of toys a (0a1000) of the next kind and their price b (0 < b10000) in grn.

#### Output

Print the number of toys with cost less than 50 grn.

Time limit 1 second
Memory limit 128 MiB
Input example #1
3
2 100.00
5 23.00
10 22.50

Output example #1
15

Source SFE-2010 Variant 27