(port-map(rec,x(let[(n(-(string-size x)1))(t 0)](if(> n 21)(dotimes(i n)(set! t(+(* t 64)(#0=modulo(-(char->ucs(ref x(+ i 1)))32)64)))(if(>(#0# i 4)0)(write-byte(#0#(ash t(*(-(#0# i 4)3)2))128)))))))read-line)
Note that non-ascii characters in the above source code will be escaped (such as \x9f).