Power Plant on the Highway

A telecom company has installed several base stations along a newly built highway. To supply power to these base stations, the company will build exactly one power plant somewhere on the highway.

The highway is the segment from point $(0, 0)$ to point $(L, 0)$ in the coordinate plane. The power plant may be placed at any point on this segment.

For a point on the highway, let $d$ be the distance from that point to its nearest base station. Among all points where the power plant could be placed, the company wants to choose the one that maximizes $d$. Find this maximum possible value of $d$.

The first line contains two integers $N$ ($1 \le N \le 10^6$) and $L$ ($1 \le L \le 10^9$), separated by a space, where $N$ is the number of base stations and $L$ is the length of the highway.

Each of the next $N$ lines contains the coordinates $x_i$, $y_i$ ($-10^9 \le x_i, y_i \le 10^9$) of a base station. All base station coordinates are distinct. The coordinates are given in increasing order of $x$; ties in $x$ are broken by increasing $y$.

The highway is the straight segment from $(0, 0)$ to $(L, 0)$, while base stations may lie anywhere in the plane.

The maximum value $d$ is always the square root of a rational number, so instead of $d$ itself, output $d^2$ as an irreducible fraction.

Writing $d^2 = \dfrac{p}{q}$ with $q \ge 1$ and $\gcd(p, q) = 1$, print it on a single line in the form p/q. Always use the p/q form, even when the denominator $q$ equals $1$ (for example, 25/1).