n, p = gets.strip.split
n = n.to_i
p = p.to_f

p2 = 1.0 - p
s = (1..n+1).map {|i| 1.0}
ans = 0.0

(2..n).each do |i|
    ans += s[i]
    (i*2..n).step(i) do |j|
        s[j] = s[j] * p2
    end
end

puts ans