import sys
stdin = sys.stdin
 
ni = lambda: int(ns())
na = lambda: list(map(int, stdin.readline().split()))
nn = lambda: list(stdin.readline().split())
ns = lambda: stdin.readline().rstrip()

n = ni()

aa = [1]
for i in range(100):
  for j in range(i+1):
    for k in range(i-j+1):
      a = '1'
      a += '1'*k
      a += '0'*j
      a += '1'*(i-j-k)
      a += '1'
      aa.append(int(a,2))

aa = list(set(aa))
aa.sort()

print(aa[n-1])