Problems

# Number of toys

# 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** (**0** ≤ **n** ≤ **1000**). Each of the next **n** lines contains **2** numbers: the number of toys **a** (**0** ≤ **a** ≤ **1000**) of the next kind and their price **b** (**0** < **b** ≤ **10000**) in grn.

#### Output

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

Input example #1

3 2 100.00 5 23.00 10 22.50

Output example #1

15