#        123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789_12
perl5.10 -E'$l=pop;sub r(){int rand 10}@x=map r,1..$l;while(@h<@x){@g=map$h[$_]//r,0..$l-1;push@h,$g[@h]if$g[@h]==$x[@h];say@g}' 16