# Prolog, <s>73</s>, <s>71</s>, 67 bytes # q(X):-X='0',write(1);write(0). p(X):-atom_chars(X,L),maplist(q,L). Not an optimal language for this challenge.<br> Having input in string-form makes for an expensive conversion to list.<br> Could probably be improved on though.<br> <br> **Testing:**<br> Try it out [here](http://swish.swi-prolog.org/)