Sonu and Monu are good friends. One day, Sonu gave a binary string of length L to Monu, and asks Monu to pick two positions a and b in the string. Now he given a number P to Monu and he have to tell what are the chances that there will be 1 on both positions and |a-b|<=P

Note: Binary String means which contains only 1 and 0.

INPUT:

First line contains T, the number of testcases. For each test-case, first line consists of two space separated integer L and P, second line consist a string of length L.

OUTPUT:

T lines contains the changes in fraction. If changes are 0, print 0/1

Constraints:

1 <= T <= 100000

1 <= L <= 100000

1 <= P <= L