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#3969
Subtask

Load Balancing 1s 512MB

Problems

Farmer John's N cows are each standing at distinct locations (x_1, y_1) \ldots (x_n, y_n) on his two-dimensional farm (1 \leq N \leq 1000, and the x_i's and y_i's are positive odd integers of size at most 1,000,000). FJ wants to partition his field by building a long (effectively infinite-length) north-south fence with equation x=a (a will be an even integer, thus ensuring that he does not build the fence through the position of any cow). He also wants to build a long (effectively infinite-length) east-west fence with equation y=b, where b is an even integer. These two fences cross at the point (a,b), and together they partition his field into four regions.

FJ wants to choose a and b so that the cows appearing in the four resulting regions are reasonably "balanced", with no region containing too many cows. Letting M be the maximum number of cows appearing in one of the four regions, FJ wants to make M as small as possible. Please help him determine this smallest possible value for M.


Input

The first line of the input contains a single integer, N. The next N lines each contain the location of a single cow, specifying its x and y coordinates.


Output

You should output the smallest possible value of M that FJ can achieve by positioning his fences optimally.


Subtask

# Score Condition
#117
#237
#346

Example

8
3 5
3 3
13 7
7 7
5 1
7 5
7 11
9 7
4


Source

USACO 2016 February Silver

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