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# Jumping Stones

**Timelimit: 2**

By Contest Road to Fortaleza V Brazil

Petr is playing a game called "Jumping Stones".

In this game, there are N slots in a line numbered from 1 to N. On each slot there is a stone with a number written on its top. The written numbers go from 1 to N and are all different.

Petr starts at slot 1 and takes K steps. At each step, he looks the number written on the current stone and jumps to the slot correspondent to that number.

Given integers N and K, determine among all possible configurations the probability that he will return to slot 1 after K steps. Assume that different configurations has the same probability.

You will be given **T**, number of test cases, and then **T** lines follow with **N** and **K** from the statement (1 <= **N**,**K** <= 10^5).

For each test case output a single line with the answer. Your answer will be considered correct if the absolute erro is less than 0.00001

**Ps.:** Following the example input For the second case we have the following possibilites:

1 2 3

1 3 2

2 1 3

2 3 1

3 1 2

3 2 1

In the first and second configurations we finish at the slot 1 after 1 step.

Sample Input | Sample Output |

2 1 1 3 1 |
1.000000 0.333333 |