from decimal import Decimal, getcontext
import sys

getcontext().prec = 1000  # Ensure high precision for accurate summation

n = int(sys.stdin.readline())
total = Decimal(0)
for _ in range(n):
    line = sys.stdin.readline().strip()
    total += Decimal(line)

# Format the result to exactly 10 decimal places
print("{0:.10f}".format(total))