while True:

    try:

        n = float(input())

        d = [0]*10

        d[0] = n

        for i in range(1,10):

            if i%2 == 0: d[i] = d[i-1]/3

            else: d[i] = d[i-1]*2

        print(round(sum(d),8))

    except:

        break
while True:

    try:

        n = float(input())

        d,c = n,n

        for i in range(1,10):

            if i%2 == 0: c = c/3

            else: c = c*2

            d += c

        print(round(d,8))

    except:

        break
while True:
    try:
        n = float(input())
        d = [0] * 10
        d[0] = n
        for i in range(1, 10):
            if i % 2 == 0:
                d[i] = d[i - 1] / 3
            else:
                d[i] = d[i - 1] * 2
        print(round(sum(d), 8))
    except:
        break

while True:
    try:
        n = float(input())
        d, c = n, n
        for i in range(1, 10):
            if i % 2 == 0:
                c = c / 3
            else:
                c = c * 2
            d += c
        print(round(d, 8))
    except:
        break

-        d = [0] * 10 -        d[0] = n +        d, c = n, n -                d[i] = d[i - 1] / 3 +                c = c / 3 -                d[i] = d[i - 1] * 2 -        print(round(sum(d), 8)) +                c = c * 2 +            d += c +        print(round(d, 8))