For given n points in metric space, find the distance of the closest points.
n x0 y0 x1 y1 : xn-1 yn-1
The first integer n is the number of points.
In the following n lines, the coordinate of the i-th point is given by two real numbers xi and yi. Each value is a real number with at most 6 digits after the decimal point.
Print the distance in a line. The output values should be in a decimal fraction with an error less than 0.000001.
2 0.0 0.0 1.0 0.0
3 0.0 0.0 2.0 0.0 1.0 1.0