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 JavaScript (node.js v5.12) (judge verdict: Time Limit Exceeded)

"use strict";
const main = arg => {
  let K = arg.split(" ")[0];
  let S = arg.split(" ")[1];
  let cnt = 0;
  for(let x = 0; x <= K; x++){
    for(let y = 0; y <= K; y++){
      for(let z = 0; z <= K; z++){
        if(x + y + z == S){
        	cnt++;
        }
      }
    }
  }
  console.log(cnt);
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'));