import std.stdio, std.conv, std.math, std.string, std.range, std.array,
       std.algorithm, std.bigint;

void main(){
  auto N = readln().strip().to!int();
  BigInt ans = "0";
  foreach(immutable int i; 0 .. N) {
    auto t = readln().strip().split('.').map!(to!string)();
    char[] tt = "0000000000".dup;
    if(t.length == 2) {
      foreach(ulong j; 0 .. t[1].length) {
        tt[j] = t[1][j];
      }
    }
    ans += BigInt(t[0] ~ tt);
  }

  auto anss = ans.to!(char[]);
  writeln( anss[0 .. $-10] ~ "." ~ anss[$-10 .. $] );
}