Problem B. Blown by the wind ≡

Statement

Young programmer Vasya wants to give Alice a birthday present. To do this, he found a beautiful one-dimensional lawn and in N integer coordinates x_i he installed a_i beautiful stones, to show Alice later.

In the morning, Vasya discovered that due to the strong wind blowing in one direction or another, some stones rolled away in different directions. Now in M integer coordinates y_i there are b_i stones.

However, the relative position of the stones could not change. Thus, if the first stone was at the coordinate x₁, and the second stone was at the coordinate x₂ > x₁, then their coordinates y will satisfy inequality y₂ ≥ y₁. Stones that were at the same x coordinates can move to different y coordinates.

Vasya wants to understand how much the arrangement of the stones has changed, so he asks you to calculate exactly how many stones were left standing in their original positions.

Input format

The first line contains the integer N.

The next N lines contain two integers each, separated by a space — x_i, a_i, in ascending order of x_i.

The next line contains the integer M.

Output format

Output the number of stones that remained in their original positions.

Constraints

1 ≤ N, M ≤ 10⁵

 − 10⁹ ≤ x_i, y_i ≤ 10⁹

1 ≤ a_i, b_i ≤ 10⁹

Sample tests

3
1 1
2 1
3 1
1
3 3

1

2
1 5
2 1
4
1 2
2 1
3 1
4 2

2