([){concatstrings}def/f{a 43 mod mul{(\))[(\()exch[exit}repeat}def{{(%stdin)(r)file
1 string readstring pop/a 1 index 0 get def a 10 eq{def =}{a 48 ge{0}{3 1 roll
dup a 47 idiv mul exch 6 mod 5 mod add f[3 1 roll 6 mod a mul 5 mod f
exch[a}ifelse}ifelse}loop}stopped
Note that non-ascii characters in the above source code will be escaped (such as \x9f).