def c(d):
 x=d%37
 if x<10:o=chr(x+48)
 elif x<36:o=chr(x+87)
 else:o="A"
 return o
while 1:
 p="";b=raw_input();a=int(b)
 while a>36:
  p=c(a)+p;a=(a-a%37)/37
 print c(a)+p