n = int(input()) total = 0 for _ in range(n): A = input() if "." in A: keta = len(A[A.find(".") + 1:]) A = A.replace(".", "") total += int(A) * 10 ** (10 - keta) else: total += int(A) * (10 ** 10) if total >= 0: print(str(total//10**10), str(total%10**10).ljust(10, '0'), sep=".") else: print(str(~total//10**10), str(10**10 - total%10**10).ljust(10, '0'), sep=".")