import sys
try:
    import os
    f = open('input.txt', 'r')
    sys.stdin = f
except FileNotFoundError:
    None
from math import sqrt, ceil
from collections import deque, Counter, defaultdict
# defaultdict(int)
input=lambda: sys.stdin.readline().strip()
sys.setrecursionlimit(11451419)
from decimal import ROUND_HALF_UP,Decimal  #変換後の末尾桁を0や0.01で指定
  #Decimal((str(0.5)).quantize(Decimal('0'), rounding=ROUND_HALF_UP))
from functools import lru_cache
from bisect import bisect_left as bileft, bisect_right as biright
from fractions import Fraction as frac  #frac(a,b)で正確なa/b
# @lru_cache(maxsize=10**10)
#######ここまでテンプレ#######
#ソート、"a"+"b"、再帰ならPython3の方がいい
#######ここから天ぷら########

n=int(input())
A=[Decimal(input()) for i in range(n)]
ans=Decimal("0")
for i in range(n):
    ans+= A[i]
print(f"{ans:.10f}")


# ans = {i:0 for i in range()}