Circle

Given N points and a circle, find how many points are inside the circle or on its circumference.
The circle is given by the coordinates of its centre - (x, y) - and its radius - R.

Input

The first line of input contains 4 integers: N, x, y, R.
Each of the following N lines contains the coordinates (xi, yi) of a point.

Output

A single integer - the number of points that are inside or on the circle.

Constraints

  • 1 ≤ N, R ≤ 104
  • -104 ≤ x, y ≤ 104
  • All coordinates are integers.
  • All points are different.

Sample

InputOutput
3 1 1 2
1 0
1 5
2 1
2
Questions?

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