#!/usr/bin/env python
def unpack_attn(a):
    if a < -128 or a > 127:
        raise ValueError ('argument out of range')

    if a < 0:
        return (128 + a) / 128.
    else:
        return (a / 19.) + 1

def pack_attn(a):
    if a < 0:
        raise ValueError ('argument is negative')

    if a < 1:
        return int (round (-128 + (a * 128)))
    else:
        return min (int (round ((a - 1) * 19)), 127)

# for a in range (-128, 128):
# print "%d -> %f" % (a, unpack_attn (a))

while 1:
    a = float (raw_input ('> '))
    if a < 0:
        break

    b = pack_attn (a)
    print "Packed: %d" % b
    print "Unpacked: %f" % unpack_attn (b)