a = input()
rlist = "0123456789ABCDEF"
acc = 0
for d in a:
    r = rlist.find(d)
    acc = acc * 16 + r
res = ""
while acc > 0:
    r = acc % 2
    res = rlist[r] + res
    acc = acc // 2
k = (4 - len(res) % 4) % 4
res = k * "0" + res
print(res)