Given an array of N integers. The task is to find the first element that occurs K number of times. If no element occurs K times the print -1.
The first line of input contains an integer T denoting the number of test cases. Then T test cases follow. The first line of each test case contains an integer N denoting the size of an array and the number K. The second line of each test case contains N space separated integers denoting elements of the array A[ ].
For each test case in a new line print the required answer.
1 <= T <= 100
1 <= N, K <= 105
1<= A <= 106
1 7 4 3 4 8 7
Both 7 and 4 occur 2 times. But 7 is the first that occurs 2 times.