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Problems

Load Balancing (Silver)

Load Balancing (Silver)

Farmer John's n cows are each standing at distinct locations (x1, y1) ... (xn, yn) on his two-dimensional farm. 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 contains a single integer n (1n1000). The next n lines each contain the location of a single cow, specifying its x and y coordinates (positive odd integers of size at most 106).

Output

Print the smallest possible value of m that FJ can achieve by positioning his fences optimally.

Time limit 1 second
Memory limit 128 MiB
Input example #1
7
7 3
5 5
7 13
3 1
11 7
5 3
9 1
Output example #1
2
Source 2016 USACO February, Silver