4348: Bear and Rectangle Strips
内存限制：256 MB
时间限制：2 S
题面：传统
评测方式：文本比较
上传者：
提交：1
通过：1
题目描述
time limit per test
3 secondsmemory limit per test
256 megabytesinput
standard inputoutput
standard outputLimak has a grid that consists of 2 rows and n columns. The j-th cell in the i-th row contains an integer ti,j which can be positive, negative or zero.
A non-empty rectangle of cells is called nice if and only if the sum of numbers in its cells is equal to 0.
Limak wants to choose some nice rectangles and give them to his friends, as gifts. No two chosen rectangles should share a cell. What is the maximum possible number of nice rectangles Limak can choose?
A non-empty rectangle of cells is called nice if and only if the sum of numbers in its cells is equal to 0.
Limak wants to choose some nice rectangles and give them to his friends, as gifts. No two chosen rectangles should share a cell. What is the maximum possible number of nice rectangles Limak can choose?
Input
The first line of the input contains an integer n (1≤n≤300000)− the number of columns in the grid.The next two lines contain numbers in the grid. The i-th of those two lines contains n integers ti,1,ti,2,...,ti,n (-109≤ti,j≤109).
Output
Print one integer, denoting the maximum possible number of cell-disjoint nice rectangles.Examples
Input
6
70 70 70 70 70 -15
90 -60 -30 30 -30 15
Output
3
Input
4
0 -1 0 0
0 0 1 0
Output
6
Input
3
1000000000 999999999 -1000000000
999999999 -1000000000 -999999998
Output
1
Note
In the first sample, there are four nice rectangles:
In the second sample, it's optimal to choose six nice rectangles, each consisting of one cell with a number 0.
In the third sample, the only nice rectangle is the whole grid− the sum of all numbers is 0. Clearly, Limak can choose at most one nice rectangle, so the answer is 1.
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