# http://c...content-available-to-author-only...e.com/a/85414/34718
L=[1]
n=input()
while n:L+=[2*L[0]+1,3*L[0]-1];n-=1;L=sorted(set(L))[1:]
print L[0]
IyBodHRwOi8vYy4uLmNvbnRlbnQtYXZhaWxhYmxlLXRvLWF1dGhvci1vbmx5Li4uZS5jb20vYS84NTQxNC8zNDcxOAoKTD1bMV0Kbj1pbnB1dCgpCndoaWxlIG46TCs9WzIqTFswXSsxLDMqTFswXS0xXTtuLT0xO0w9c29ydGVkKHNldChMKSlbMTpdCnByaW50IExbMF0=