i;main(n,_){for(printf("Gray code n=%d",n=getchar()-48);i>>n<n;)printf(!!(i++%n)+"\n%d",(i/n*2^i/n)>>n-i%n&1);}
//i;main(n,_){for(printf("Gray code n=%d",n=_%9+7);i>>n<n;)printf(!!(i++%n)+"\n%d",(i/n*2^i/n)>>n-i%n&1);}
Note that non-ascii characters in the above source code will be escaped (such as \x9f).