Monocarp is playing a tower defense game. A level in the game can be represented as an OX axis, where each lattice point from $$$1$$$ to $$$n$$$ contains a tower in it.

The tower in the $$$i$$$-th point has $$$c_i$$$ mana capacity and $$$r_i$$$ mana regeneration rate. In the beginning, before the $$$0$$$-th second, each tower has full mana. If, at the end of some second, the $$$i$$$-th tower has $$$x$$$ mana, then it becomes $$$\mathit{min}(x + r_i, c_i)$$$ mana for the next second.

There are $$$q$$$ monsters spawning on a level. The $$$j$$$-th monster spawns at point $$$1$$$ at the beginning of $$$t_j$$$-th second, and it has $$$h_j$$$ health. Every monster is moving $$$1$$$ point per second in the direction of increasing coordinate.

When a monster passes the tower, the tower deals $$$\mathit{min}(H, M)$$$ damage to it, where $$$H$$$ is the current health of the monster and $$$M$$$ is the current mana amount of the tower. This amount gets subtracted from both monster's health and tower's mana.

Unfortunately, sometimes some monsters can pass all $$$n$$$ towers and remain alive. Monocarp wants to know what will be the total health of the monsters after they pass all towers.

Input

The first line contains a single integer $$$n$$$ ($$$1 \le n \le 2 \cdot 10^5$$$) — the number of towers.

The $$$i$$$-th of the next $$$n$$$ lines contains two integers $$$c_i$$$ and $$$r_i$$$ ($$$1 \le r_i \le c_i \le 10^9$$$) — the mana capacity and the mana regeneration rate of the $$$i$$$-th tower.

The next line contains a single integer $$$q$$$ ($$$1 \le q \le 2 \cdot 10^5$$$) — the number of monsters.

The $$$j$$$-th of the next $$$q$$$ lines contains two integers $$$t_j$$$ and $$$h_j$$$ ($$$0 \le t_j \le 2 \cdot 10^5$$$; $$$1 \le h_j \le 10^{12}$$$) — the time the $$$j$$$-th monster spawns and its health.

The monsters are listed in the increasing order of their spawn time, so $$$t_j \lt t_{j+1}$$$ for all $$$1 \le j \le q-1$$$.

Output

Print a single integer — the total health of all monsters after they pass all towers.

Tower Defense

Examples