#!/usr/bin/perl -l $_=pop;{print;s/(?<=.).(?=.)/$&$&/g;s/../$&+0?$&%9||9:0/eg&&redo}
#!/usr/bin/perl {print$_=pop,$/;--pos,$ARGV[0].=0+$&?$&%9||9:0while/../g;@ARGV&&redo}