must be written in java

#Special Tickets

#You are given a number 1 N 50. Every ticket has two N-digit numbers. We call a ticket special, if the sum of its first N digits is equal to the sum of its last N digits. You are also given the sum of ALL digits in the number. Your task is to count an amount of special numbers, having the specified sum of ALL digits.

#Input

Two space-separated numbers: N and S. Here S is the sum of all digits. Assume that 0 S 1000.

Output

The amount of special tickets.

Sample

Notes

The special tickets are 0101, 0110, 1001, 1010 in the example above

input	output
22	4