k = io.read("*n")
e = {0, 0, 0, 0, 0, 0}
for i = 1, k do
    a = 1
    for j = 1, 6 do a = a + e[j] / 6 end
    for j = 1, 5 do e[j] = e[j + 1] end
    e[6] = a
end
print(a)