n = int(input())
ans = 0
for i in range(n):
    a = input()
    
    point = a.find('.')
    
    if point == -1:
        a = int(a) * (10 ** 10)
    else:
        if a[0] == '-':
            head = a[1:point]
            tail = a[point+1:]
            a = int(head) * (10 ** 10) + int(tail) * (10 ** (10 - len(tail)))
            a *= -1
        else:
            head = a[0:point]
            tail = a[point+1:]
            a = int(head) * (10 ** 10) + int(tail) * (10 ** (10 - len(tail)))
    
    ans += a

ans = str(ans)
print(ans[0:len(ans)-10] + '.' + ans[len(ans)-10:])