import java.util.*; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n = sc.nextInt(); long big = 0; long small = 0; for (int i = 0; i < n; i++) { char[] arr = sc.next().toCharArray(); long x = 0; long y = 0; int count = 0; boolean isPlus = true; boolean hasDot = false; for (int j = 0; j < arr.length || (hasDot && count < 10); j++) { if (!hasDot && arr[j] == '-') { isPlus = false; } else if (!hasDot && arr[j] == '.') { hasDot = true; } else { if (!hasDot) { x *= 10; x += arr[j] - '0'; } else { y *= 10; count++; if (j < arr.length) { y += arr[j] - '0'; } } } } if (isPlus) { big += x; small += y; } else { big -= x; small -= y; } } if (small <= -10000000000L) { big += small / 10000000000L; small = -(-small % 10000000000L); } else if (small >= 10000000000L) { big += small / 10000000000L; small %= 10000000000L; } if (small < 0) { if (big >= 0) { big--; small = 10000000000L + small; } else { small = -small; } } else { if (big < 0) { big++; small = 10000000000L - small; } } System.out.print(big + "."); System.out.printf("%010d\n", small); } }