You are given $n$ elements to be inserted into a priority queue. Each element is represented in the format $(x,y),$ where $x$ is the value of the element, and $y$ of $y$ indicate higher priority. If two elements share the same priority, the elements inserted first will take precedence.

Your task is to write a program to find the sum of the elements that are removed with the highest priority.

Read the input from STDIN and print the output to STDOUT. Do not write arbitrary strings while reading the input or while printing, as these contribut

Constraints:

$x$ and $y$ should not be negative.

Input Format:

The first line of input contains $N,$ where $N$ denotes the number of elements.

Next $N$ lines of input contain $xy$ where $x$ is the element and $y$ is its priority.

The last line of input contains $K$ where $K$ denotes the number of elements to be removed from the queue

Output Format:

The output contains the sum of elements removed from the priority queue.

Sample Input$1$:

$5$

$24$

$53$

$61$

$74$

$94$