Lines

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Problem

On the plane you are given a set AA of nn points. The distance from a line pp to the set AA is the largest of the distances from the points of AA to the line pp.

Among all lines that pass through a fixed point PP, choose the one whose distance to AA is as small as possible, and report that smallest distance.

Write a program that:

  • reads the set AA and the point PP from standard input,
  • computes the minimum possible distance from a line through PP to the set AA,
  • writes that value to standard output.

Input

The first line contains one integer nn (1n1000001 \le n \le 100000).

The second line contains two integers: the coordinates of the point PP.

Each of the next nn lines contains two integers: the coordinates of one point of the set AA.

All coordinates are integers whose absolute value does not exceed 10610^6.

Output

Print exactly one real number: the required distance, written with exactly three digits after the decimal point and rounded down (truncated).

The tests are chosen so that any answer within 10610^{-6} of the exact value gives the correct result after this rounding, so computing the distance to about six decimal places of accuracy is enough.