import java.util.*;

class Main{
	public static void main(String[] args){
		Scanner sc= new Scanner(System.in);
		while(true){
			String[] line =sc.nextLine().split(" ");
			int n = Integer.parseInt(line[0]);
			int x = Integer.parseInt(line[1]);
		//break	
			if(n==0 && x==0){
				break;
			}
			System.out.println(sum(n,x));
		}					

	}
	public static int sum(int n,int x){
		int count=0;
		for(int i=0;i<n;i++){
			for(int j=0;j<i;j++){
				for(int k=0;k<j;k++){
					if(x-3==i+j+k){
						count=count+1;
					}
				}
			}
		}
		return count;
	}
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz