sub fullscore {
  $_=join'',@_;                                                 # 13

  s/^(X|\d.){10}$/$&0/;                                         # 21

  s#(.)/(?=(.).|.?$)#$1.($1?10-$1:'x').lc$2#ge;                 # 45

  s/X(?=(..).)/X$1/g;                                           # 19

  y/Xx/9/+eval join'+',/./g                                     # 25
}
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