def main():
    M, N = map(int, input().split())
    E = M
    for _ in range(N):
        E =(E*2 + (E+1) + 0)/3
    if str(E)[-2:] ==".0":
        E = int(E)
    else:
        E = round(E*10**12) / 10**12
    return E

if __name__ == '__main__':
    print(main())