def inp() a=gets.chomp.split(" ").map(&:to_i)end def inpf() a=gets.chomp.split(" ").map(&:to_f)end def inps() a=gets.chomp.split(" ")end def copy(a) Marshal.load(Marshal.dump(a)) end def kaizyo(n)(n < 2)? 1 : (2..n).inject(:*) end def scount(a) b=na(a.max+1);a.each{|n|b[n]+=1};return b end def na(n,d=0) Array.new(n,d)end def na2(n,m,d=0) Array.new(n){Array.new(m,d)}end def na3(n,m,l,d=0) Array.new(n){Array.new(m){Array.new(l,d)}}end def bit(n) a.to_s(2).split("").map(&:to_i) end n = inp[0] b = inp[0] lis = [] a = inpf ans = 0.0 a.each do |f| ans += f*b**(f-1) end p ans ans = 0 ans = 0.0 a.each do |f| if(f+1 != 0) ans += b**(f+1)/(f+1) else ans += Math.log(b) end end p ans =begin =end