# http://c...content-available-to-author-only...e.com/a/85414/34718
L=1,;exec'L+=2*L[0]+1,3*L[0]-1;L=sorted(set(L))[1:];'*input()
print L[0]
IyBodHRwOi8vYy4uLmNvbnRlbnQtYXZhaWxhYmxlLXRvLWF1dGhvci1vbmx5Li4uZS5jb20vYS84NTQxNC8zNDcxOAoKTD0xLDtleGVjJ0wrPTIqTFswXSsxLDMqTFswXS0xO0w9c29ydGVkKHNldChMKSlbMTpdOycqaW5wdXQoKQpwcmludCBMWzBd