You have N subjects in a course and you are given following information about the subjects: Each subject has two integers \(start\) and \(end\) which represents the study time starting from \(start[i]\) to \(end[i]\) to each of the i^th subject(1 ≤ i ≤ N) .

There are no two distinct subjects X and Y such that \(start[X] ≤ start[Y]\) and \(end[Y] ≤ end[X]\), which means that there is no subject whose studying interval is completely present inside the other subject studying interval. You are required to write a program to assign each subject a new interval of time such that all the N new intervals are assigned according to the following rules:

No two new intervals, X and Y should intersect for \(1 <=X <=N\) , \(1<=Y<=N\) and X not equal to Y. It means, if interval X lies between A and B then no other new interval should lie in this range.
New interval is a sub interval of the later one which means that if interval X lies in range \(A<=X<=B\) and if Y is new interval then it must also lie within this range only.
All new intervals are of equal length so that you can provide proper time to each subject.

Input Format :
First line contains number of test cases T.
Each test case in it's first line contains N — the number of subjects.
Each of the next N lines contains information about one of the subject's studying interval — two integer numbers \(start\) and \(end\).

Output Format :
Print the maximal possible length of an interval in an irreducible fraction \(p/q\)

Input Constraints :
\(1 <= T <=10\)
\(1 <= N <=10^5\)
\(0 ≤ start[i] < end[i] ≤ 10^6\) for all i between 1 to N

Note
Data provided in the input file confirms to the conditions laid out in the problem statement that is there are no two distinct X and Y such that start[X] ≤ start[Y] and end[Y] ≤ end[X]. Also each interval can have maximum precision that can be computed.

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