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 Java8 (OpenJDK 1.8.0) (judge verdict: Time Limit Exceeded)

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		SumOfThreeIntegers solver = new SumOfThreeIntegers();
		solver.readInput();
		solver.solve();
		solver.writeOutput();
	}

	static class SumOfThreeIntegers {
		private int k;
		private int s;
		private Scanner scanner;
		private int output;

		public SumOfThreeIntegers() {
			scanner = new Scanner(System.in);
			output = 0;
		}

		public void readInput() {
			k = scanner.nextInt();
			s = scanner.nextInt();
		}

		public void solve() {

			for(int x=0; x<=k;x++)
				for(int y=0; y<=k; y++)
					for(int z=0; z<=k; z++)
						if(x+y+z == s)
							output++;
		}

		public void writeOutput() {
			System.out.print(output);
		}

	}

}