CT14E  Camels
Bob likes to draw camels: with a single hump, two humps, three humps, etc. He draws a camel by connecting points on a coordinate plane. Now he's drawing camels with t humps, representing them as polylines in the plane. Each polyline consists of n vertices with coordinates (x_{1}, y_{1}), (x_{2}, y_{2}), ... (x_{n}, y_{n}). The first vertex has a coordinate x_{1} = 1, the second x_{2} = 2, etc. Coordinates y_{i} might be any, but should satisfy the following conditions:
 there should be t humps precisely, i.e. such indexes j (2 ≤ j ≤ n  1), so that y_{j  1} < y_{j} > y_{j + 1},
 there should be precisely t  1 such indexes j (2 ≤ j ≤ n  1), so that y_{j  1} > y_{j} < y_{j + 1},
 no segment of a polyline should be parallel to the Oxaxis,
 all y_{i} are integers between 1 and 4.
For a series of his drawings of camels with t humps Bob wants to buy a notebook, but he doesn't know how many pages he will need. Output the amount of different polylines that can be drawn to represent camels with t humps for a given number n.
Input
The first line of input contains the number of test cases, N.
Each test case contains a pair of integers n and t (3 ≤ n ≤ 20, 1 ≤ t ≤ 10).
Output
For each testcase, output the required number of camels with t humps.
Example
Input: 1 6 1 Output: 6
Note In the first sample test sequences of ycoordinates for six camels are: 123421, 123431, 123432, 124321, 134321 and 234321 (each digit corresponds to one value of y_{i}).
hide comments
joeon:
20210802 17:54:29
The fact is you really need to check the title 

Phan Công Minh:
20100603 01:41:01
Thanks . I've fixed the error. 

Jorge Bernadas:
20100603 01:40:54
No, really you have to check your sample input, it should be:


AM_PM:
20100603 01:40:54
Please check the limits in the input file ! Last edit: 20100602 19:16:59 
Added by:  Phan Công Minh 
Date:  20100602 
Time limit:  1s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: NODEJS OBJC PERL6 SQLITE VB.NET 
Resource:  Codeforces. 