while line = gets
  n,x = line.split(" ").map { | val | val.to_i}
  break if 0 == n && 0 == x

  cnt = 0
  ave = x/3
  for i in (1..ave-1 )    
    ave2 = (x-i) / 2
    for j in (i+1..ave2 )
      k = x-i-j
      if j < k && k<= n
        cnt += 1
      end
    end
  end

 puts ( cnt )
 end