IOI '04 - Athens, Greece
Zeus gave Artemis, the goddess of the wilderness, a rectangular area for
growing a forest. With the left side of the area as a segment of the
positive
-axis and the bottom side as a segment of the positive
-axis,
and
the left bottom corner of the area, Zeus told Artemis to plant
trees only on integer coordinate points in the area. Artemis liked the
forest to look natural, and therefore planted trees in such a way that a
line connecting two trees was never parallel to
-axis or
-axis.
At times, Zeus wants Artemis to cut trees for him. The trees are to be
cut as follows:
- Zeus wants at least a given number
of trees to be cut for him.
- To get a rectangular football pitch for future football success,
Artemis is to cut all trees within a rectangular area, and no trees
outside of it.
- The sides of this rectangular area are to be parallel to
-axis and
-axis.
- Two opposite corners of the area must be located on trees and
therefore those corner trees are also cut.
As Artemis likes the trees, she wants to fulfill these conditions whilst
cutting as few trees as possible. You are to write a program that, given
information on the forest and the minimum number
of trees to be cut,
selects an area for cutting trees for Artemis.
Input Specification
The first line contains one integer
: the
number of trees in the forest. The second line contains one integer
: the minimum number of trees to be cut. The following
lines describe the positions of the
trees. Each of these lines
contains two integers
and
: the
-coordinate followed by the
-coordinate of a tree.
Output Specification
The output is to contain one line with two integers
and
separated by one space: Artemis should use the
-th tree
(with position given on line
of the input file) and
-th tree (with position given on line
of the input
file) as the corners of the area for cutting trees. The order of these
two numbers is irrelevant. There may be several ways to choose these
trees and you need to find and output one of them. For all test cases at
least one solution exists.
Sample Input
Copy
3
2
1 1
2 3
5 6
Sample Output
Copy
1 2
Note: in
of the inputs,
.
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