[Usaco2005 mar]Space Elevator 太空电梯

The cows are going to space! They plan to achieve orbit by building a sort of space elevator: a giant tower of blocks. They have K (1 <= K <= 400) different types of blocks with which to build the tower. Each block of type i has height h_i (1 <= h_i <= 100) and is available in quantity c_i (1 <= c_i <= 10). Due to possible damage caused by cosmic rays, no part of a block of type i can exceed a maximum altitude a_i (1 <= a_i <= 40000). Help the cows build the tallest space elevator possible by stacking blocks on top of each other according to the rules.

牛们要到太空去了！他们打算建造一座太空电梯来送他们进入轨道。

有K(1≤K≤400)种方块，第i种有一个特定的高度h_i(1≤h_i≤100)，一定的存量c_i(1≤c_i≤10)。为防宇宙射线的破坏，第i种方块的任何部分不能超过高度a_i(1≤a_i≤40000)。请用这些方块堆出最高的太空电梯。

输入描述

• 英文描述：
  • Line 1: A single integer, K
  • Lines 2..K+1: Each line contains three space-separated integers: h_i, a_i, and c_i. Line i+1 describes block type i.
• 中文描述：
  • 第1行：一个整数K
  • 第2到K+1行：每行包含三个空格分隔的整数h_i, a_i, c_i，分别描述第i种方块的属性

输出描述

• 英文描述：
  • Line 1: A single integer H, the maximum height of a tower that can be built
• 中文描述：
  • 第1行：一个整数H，表示能建造的塔的最大高度

输入样例1

3
7 40 3
5 23 8
2 52 6

输出样例1

48

提示

从底部开始，先放3个方块2，之后3个方块1，接下来6个方块3。不能把3个方块1堆到4个方块2上，因为这样最高的方块1的顶部高度超过了40。