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: Wrong Answer)

function combination(input) {
	var max = input.split(" ")[0];
	var sum = input.split(" ")[1];
	var count = 0;
	if(sum <= max){
		for(var x = 0; x < sum+1; x++){
			for(var y = 0; y < sum+1-x; y++){
				for(var z = 0; z < sum+1-x-y; z++){
					if(z===sum-x-y){
						count++;
					}
				}
			}
		}
	} else if (sum > max){
		for(var x = 0; x < max+1; x++){
			if(sum-x <= max){
				for(var y = 0; y < sum+1-x; y++){
					for(var z = 0; z < sum+1-x-y; z++){
						if(z===sum-x-y){
							count++;
						}
					}
				}
			}else if(sum-x > max){
				for(var y = 0; y < max+1; y++){
					if(sum-x-y <= max){
						for(var z = 0; z < sum+1-x-y; z++){
							if(z===sum-x-y){
								count++;
							}
						}
					}else if(sum-x-y > max){

					}
				}
			}
		}
	}
	console.log(count);
}

combination(require("fs").readFileSync("/dev/stdin", "utf8"));