Problem:
Score : 200 points

Problem Statement

You are given two integers K and S.

Three variable X, Y and Z takes integer values satisfying 0≤X,Y,Z≤K.

How many different assignments of values to X, Y and Z are there such that X + Y + Z = S?

Constraints

2≤K≤2500

0≤S≤3K

K and S are integers.

Input

The input is given from Standard Input in the following format:

K S

Output

Print the number of the triples of X, Y and Z that satisfy the condition.

Sample Input 1

2 2

Sample Output 1

6

There are six triples of X, Y and Z that satisfy the condition:

X = 0, Y = 0, Z = 2

X = 0, Y = 2, Z = 0

X = 2, Y = 0, Z = 0

X = 0, Y = 1, Z = 1

X = 1, Y = 0, Z = 1

X = 1, Y = 1, Z = 0

Sample Input 2

5 15

Sample Output 2

1

The maximum value of X + Y + Z is 15, achieved by one triple of X, Y and Z.

Solution in C# (Mono 4.6.2.0) (judge verdict: Runtime Error)

using System;
    class Program
    {
        static void Main(string[] args)
        {
            int k,s,result = 0;
            k = int.Parse(Console.ReadLine());
            s = int.Parse(Console.ReadLine());

            for (int i = 0; i <= k; i++)//S-
            {
                for (int ii = 0;ii <= s - i && ii <= k ; ii++)
                {
                    for (int iii = 0; iii<= s-i-ii && iii <= k; iii++)
                    {
                        if (s - i - ii- iii == 0 )
                        {
                            result++;
                        }
                    }

                }
            }
            Console.WriteLine(result);
        }
    }