CF1651F.Tower Defense

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.

Monocarp 正在玩一款塔防游戏。游戏中的一关可以表示为一条 $OX$ 轴，其中从 $1$ 到 $n$ 的每个整数坐标点上都有一座塔。

第 $i$ 座塔的法力容量为 $c_i$，法力恢复速率为 $r_i$。初始时（即第 $0$ 秒之前），每座塔均拥有满法力。若某座塔在某一秒结束时拥有 $x$ 点法力，则它在下一秒开始时的法力值为 $\mathit{min}(x + r_i, c_i)$。

本关中共有 $q$ 只怪物生成。第 $j$ 只怪物于第 $t_j$ 秒初在坐标点 $1$ 处生成，其生命值为 $h_j$。每只怪物每秒沿坐标增大的方向移动 $1$ 个单位距离。

当一只怪物经过某座塔时，该塔对其造成 $\mathit{min}(H, M)$ 点伤害，其中 $H$ 是怪物当前的生命值，$M$ 是该塔当前的法力值。该伤害值将同时从怪物的生命值和塔的法力值中扣除。

不幸的是，有时部分怪物可能成功穿过全部 $n$ 座塔并依然存活。Monocarp 想知道：所有怪物穿过全部塔之后，它们剩余生命值的总和是多少？

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 $1 \le j \le q-1$.

第一行包含一个整数 $n$（$1 \le n \le 2 \cdot 10^5$）—— 塔的数量。

接下来的 $n$ 行中，第 $i$ 行包含两个整数 $c_i$ 和 $r_i$（$1 \le r_i \le c_i \le 10^9$）—— 第 $i$ 座塔的法力容量与法力恢复速率。

接下来一行包含一个整数 $q$（$1 \le q \le 2 \cdot 10^5$）—— 怪物的数量。

接下来的 $q$ 行中，第 $j$ 行包含两个整数 $t_j$ 和 $h_j$（$0 \le t_j \le 2 \cdot 10^5$；$1 \le h_j \le 10^{12}$）—— 第 $j$ 只怪物的生成时间及其生命值。

怪物按生成时间升序列出，即对所有 $1 \le j \le q-1$，均有 $t_j \lt t_{j+1}$。

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

输出一个整数——所有怪物经过所有塔后的总生命值。