YY's new problem

Problem Description
Given a permutation P of 1 to N, YY wants to know whether there exists such three elements P[i1], P[i2], P[i3] that
P[i1]-P[i2]=P[i2]-P[i3], 1<=i1<i2<i3<=N.

Input
The first line is T(T<=60), representing the total test cases.
Each test case comes two lines, the former one is N, 3<=N<=10000, the latter is a permutation of 1 to N.

Output
For each test case, just output 'Y' if such i1, i2, i3 can be found, else 'N'.

Sample Input
2
3
1 3 2
4
3 2 4 1

Sample Output
N
Y