n = int(input())
ans = 0
for i in range(n):
    s = input()
    m = 1
    if s[0] == "-":
        m = -1
        s = s[1:]
    x = 0
    while x < len(s) and s[x] != ".":
        x += 1
    p = 0
    for j in range(x):
        p *= 10
        p += ord(s[j]) - ord("0")
    c = 10
    for j in range(x + 1, len(s)):
        p *= 10
        p += ord(s[j]) - ord("0")
        c -= 1
    while c >= 1:
        c -= 1
        p *= 10
    ans += m * p
l = ans // 10000000000
ans %= 10000000000
e = ""
if l < 0:
    e = "-"
    ans -= 10000000000
    ans = -ans
    l += 1
    l = -l
s = ""
while len(s) < 10:
    s += chr(ord("0") + ans % 10)
    ans //= 10
s_reversed_list = list(reversed(s))
s_reversed = "".join(list(reversed(s)))
print(e, l, ".", s_reversed, sep="")