[Usaco2005 mar]Space Elevator 太空电梯

时间限制:5s      空间限制:64MB

题目描述

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)神方块,第i种有一个特定的高度hi(l≤hi≤100),一定的存量ci(l≤ci≤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ai(l≤ai≤40000). 请用这些方块堆出最高的太空电梯.


输入格式

* 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.

 
    第1行输入一个整数K.
    接下来K行,每行输入三个整数hi,ai,ci.


输出格式

* Line 1: A single integer H, the maximum height of a tower that can be built

 
    一个整数,表示最大高度.


样例输入

3
7 40 3
5 23 8
2 52 6


样例输出

48
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.

提示

没有写明提示


题目来源

Gold