N = gets.to_i
K = gets.to_i
def f(n, m)
  @dp ||= {}
  @dp[[n, m]] ||= if n == 0 and m == 0
                    1.0
                  elsif n == 0 or m <= 0
                    0.0
                  elsif n <= K
                    (4..6).map {|i| f(n - 1, m - i)}.inject(:+) / 3
                  else
                    (1..6).map {|i| f(n - 1, m - i)}.inject(:+) / 6
                  end
end
def g(n, m)
  @dp2 ||= {}
  @dp2[[n, m]] ||= if n == 0 and m == 0
                    1.0
                  elsif n == 0 or m <= 0
                    0.0
                  else
                    (1..6).map {|i| g(n - 1, m - i)}.inject(:+) / 6
                  end
end
ans = ((N + 1)..(6 * N)).map {|m| f(N, m) * (N...m).map {|l| g(N, l)}.inject(:+)}.inject(:+)
puts ans