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
Note that non-ascii characters in the above source code will be escaped (such as \x9f).