require 'bigdecimal'
require 'bigdecimal/math'
N = gets.to_i
sum = BigDecimal.new("0.00000000000000000000");
for i in 1..N
  a = gets;
  sum += BigDecimal.new(a)
end
s = sum.to_s("F");
d = 0
f = false
for i in 0..s.length()-1
  if d == 10
    break;
  end
  print(s[i])
  if f
    d+=1
  end
  if s[i]=='.'
    f = true
  end
end
for i in d..9
  print("0")
end
print("\n")