_==0 "exec" "gawk" "-f" "$0"
BEGIN { for(i=0;i<=9;i++) y[i]=1 }
/S$/ { for(k in y) if(index($0,k)==0) delete y[k] }
/O$/ { for(i=1;i<=7;i+=2) n[substr($0,i,1)]=1 }
END { for(k in n) delete y[k]; for(k in y) print k }