write a go solution for Description:
Vova has recently learned what a circulaton in a graph is. Recall the definition: let G=(V,E) be a directed graph. A circulation f is such a collection of non-negative real numbers f_e (einE), that for each vertex vinV the following conservation condition holds:

\sum\limits_{e \in \delta^{-}(v)} f_e = \sum\limits_{e \in \delta^{+}(v)} f_e

where delta^+(v) is the set of edges that end in the vertex v, and delta^-(v) is the set of edges that start in the vertex v. In other words, for each vertex the total incoming flow should be equal to the total outcoming flow.

Let a lr-circulation be such a circulation f that for each edge the condition l_e<=qf_e<=qr_e holds, where l_e and r_e for each edge einE are two non-negative real numbers denoting the lower and upper bounds on the value of the circulation on this edge e.

Vova can't stop thinking about applications of a new topic. Right now he thinks about the following natural question: let the graph be fixed, and each value l_e and r_e be a linear function of a real variable t:

l_e(t) = a_e t + b_e r_e(t) = c_e t + d_e

Note that t is the same for all edges.

Let t be chosen at random from uniform distribution on a segment [0,1]. What is the probability of existence of lr-circulation in the graph?

Input Format:
The first line contains two integers n, m (1<=qn<=q1000, 1<=m<=2000).

Each of the next m lines describes edges of the graph in the format u_e, v_e, a_e, b_e, c_e, d_e (1<=u_e,v_e<=n, -10^4<=a_e,c_e<=10^4, 0<=b_e,d_e<=10^4), where u_e and v_e are the startpoint and the endpoint of the edge e, and the remaining 4 integers describe the linear functions for the upper and lower bound of circulation.

It is guaranteed that for any tin[0,1] and for any edge einE the following condition holds 0<=ql_e(t)<=qr_e(t)<=q10^4.

Output Format:
Print a single real integer — the probability of existence of lr-circulation in the graph, given that t is chosen uniformly at random from the segment [0,1]. Your answer is considered correct if its absolute difference from jury's answer is not greater than 10^-6.

Note:
In the first example the conservation condition allows only circulations with equal values f_e for all three edges. The value of circulation on the last edge should be 4 whatever t is chosen, so the probability is

P(4 \in [3, -4t + 7]~~\&~~4 \in [-2t + 5, t + 6]) = 0.25. Output only the code with no comments, explanation, or additional text.