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

void main(){
  auto N = readln().strip().to!int();
  long ansi;
  real ansd = 0;
  foreach(immutable int i; 0 .. N) {
    auto t = readln().strip().to!real();
    auto ti = t.to!long();
    ansi += ti;
    ansd += t - ti;

    auto td = ansd.to!long();
    ansi += td;
    ansd -= td;
  }

  write(ansi, ".");
  foreach(int i; 0 .. 10) {
    ansd *= 10;
    auto t = ansd.to!int();
    ansd -= t;
    write(t);
  }

  writeln();
}