题目描述
Problem Statement
Two wizards, X and Y, are fighting with a monster.
Initially, each of the wizards has a magic power of 0. They know the following two spells.
- Spell 1: Increases the caster's magic power by 1.
- Spell 2: Deals damage equal to the caster's magic power to the monster.
After each wizard uses a spell N times, they will withdraw from the battle.
For each $i=1, \ldots, N,$ they must use one of the following combinations of spells for their i-th spells.
- X casts Spell a_i, and Y casts Spell b_i.
- X casts Spell c_i, and Y casts Spell d_i.
Find the maximum total damage that can be dealt to the monster before the withdrawal.
Input
Input is given from Standard Input in the following format:
N
a_1 b_1 c_1 d_1
$\vdots$
a_N b_N c_N d_N
Output
Print the answer.
Constraints
- $1 \leq N \leq 8000$
- $a_i,b_i,c_i,d_i \in$ {1,2}
- All values in input are integers.
Sample Input 1
3
1 1 2 2
2 1 2 2
2 1 1 1
Sample Output 1
3
The maximum total damage can be achieved as follows.
- As the 1-st spells, use a_1=1,\, b_1=1, increasing both X's and Y's magic powers to 1.
- As the 2-nd spells, use c_2=2,\, d_2=2, dealing 2 points of damage in total.
- As the 3-rd spells, use a_3=2,\, b_3=1, dealing 1 point of damage by X's spell and increasing Y's magic power to 2.
Sample Input 2
5
2 2 2 2
2 2 2 2
2 2 2 2
2 2 2 2
2 2 2 2
Sample Output 2
0
Casting Spell 2 with a magic power of 0 deals no damage.
Sample Input 3
8
1 1 2 2
2 2 2 1
1 1 2 1
1 1 2 2
2 1 1 1
1 2 1 2
2 1 1 2
2 1 2 1
Sample Output 3
20
Sample Input 4
20
2 1 2 1
2 1 1 1
1 2 1 1
2 2 1 2
2 2 2 1
1 1 2 1
1 2 2 2
2 2 2 1
1 1 1 2
1 2 1 2
1 2 2 2
2 1 1 2
2 1 1 1
1 2 1 2
1 2 1 2
1 1 1 2
1 1 2 1
2 2 1 1
1 2 2 2
2 1 1 2
Sample Output 4
138
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分