from decimal import Decimal


n = int(input())

ans = Decimal(0.0)

for i in range(n):
    x = Decimal(input()) 
    ans += x

ans = str(ans)
if '.' not in ans:
    ans += '.' + '0' * 10
else:
    now = ans.index('.')
    ans += '0' * (10 - (len(ans) - now - 1))
print(ans)