4 2 1 1(%stdin)run bitshift{0}repeat{3 copy 4 eq{4 count 1 roll}if( /\\_
)1 index 1 getinterval print 3 eq{eq{exit}if 0}{xor 1 index xor 3 and}ifelse count 1 roll}loop(\\)=
Note that non-ascii characters in the above source code will be escaped (such as \x9f).