import std.stdio;
import std.string;
import std.conv;
import std.algorithm;
//------------------
void main(){
  auto n = readln.chomp.to!int;
  real[] arr;
  foreach(i; 0..n){ arr ~= readln.chomp.to!real; }
  auto res = arr.reduce!((a, b) => a + b);
  writefln("%1.10f", res);
}