n = int(input())
sum_val = 0

for _ in range(n):
    s = input().strip()
    sign = 1
    if s.startswith('-'):
        sign = -1
        s = s[1:]
    parts = s.split('.', 1)
    integer_str = parts[0] if parts else '0'
    decimal_str = parts[1] if len(parts) > 1 else ''
    decimal_str = decimal_str.ljust(10, '0')[:10]  # Ensure exactly 10 digits
    integer_part = int(integer_str) if integer_str else 0
    decimal_part = int(decimal_str)
    value = sign * (integer_part * 10**10 + decimal_part)
    sum_val += value

# Convert sum_val to the desired format string
if sum_val == 0:
    print("0.0000000000")
else:
    sign = '-' if sum_val < 0 else ''
    digits = str(abs(sum_val))
    if len(digits) < 10:
        padded = digits.zfill(10)
        integer_part_str = '0'
        decimal_part_str = padded
    else:
        integer_part_str = digits[:-10].lstrip('0') or '0'
        decimal_part_str = digits[-10:]
    # Ensure decimal_part_str is exactly 10 characters
    decimal_part_str = decimal_part_str.ljust(10, '0')[:10]
    print(f"{sign}{integer_part_str}.{decimal_part_str}")