p/0000a loop m/1001a/1100a/1000a/1011a/0111a/1010a/0110a/1001a/0101a/1000a/g s/a(.)/\1a/g m/0([01]{4}a)/\1/1([01]{4}a)/0001a\1/ e/a$/ end s/^0+a// m/0000a/0/0001a/1/0010a/2/0011a/3/0100a/4/0101a/5/0110a/6/0111a/7/1000a/8/1001a/9/g