n = int(input())
ans = 0
A = [input() for _ in range(n)]
for i in range(n):
    if A[i].find(".") == -1: #小数点なし
        ans += int(A[i]) * 10**10
    else:
        pt = A[i].find(".")
        floatdigit = len(A[i]) - pt - 1
        A[i] = A[i].replace(".","")
        if A[i][0] == "-":
            A[i] = "-" + str(int(A[i][1:] + "0" * (10-floatdigit)))
        else:
            A[i] = str(int(A[i] + "0" * (10-floatdigit)))
        ans += int(A[i])
ans = str(ans)
ans = ans[:len(ans)-10] + "." + ans[len(ans)-10:]
print(ans)