y =| cos(2x)|#2046
Determine whether the point , given by coordinates (x_0, y_0), belongs to the region of the plane bounded by the segment of the -axis from -\frac{\pi}{2} to \frac{\pi}{2} and the cosine curve y = |\cos(2x)|.
The single line contains the coordinates of the point (x_0, y_0). The values of the coordinates do not exceed in absolute value.
Output a single line with one of the following messages:
YES — if the point belongs to this region of the plane;
NO — if it does not belong;
ON BORDER — if the point is on one of the boundary lines of the specified region. For this problem, assume that the point is on a boundary if, for the same abscissa, the distance along the ordinate to one of the boundary lines is no more than ; or for the same ordinate, the distance along the abscissa to one of the boundary lines is also no more than .
Example 1