05

def F(n):
  bn = bin(n)[2:]
  if n % 2 == 0:
    bn = "1" + bn + "0"
  else:
    bn = "11" + bn + "11"
  return int(bn, 2)

mn = 100000
for n in range(1, 1000):
  r = F(n)
  if r > 52:
    mn = min(mn, r)
print(mn)